/src/com/vaadin/client/ui/VCustomScrollTable.java

Large files files are truncated, but you can click here to view the full file

/*
 * Copyright 2000-2014 Vaadin Ltd.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.vaadin.client.ui;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.dom.client.Node;
import com.google.gwt.dom.client.NodeList;
import com.google.gwt.dom.client.Style;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Overflow;
import com.google.gwt.dom.client.Style.Position;
import com.google.gwt.dom.client.Style.TextAlign;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.dom.client.Style.Visibility;
import com.google.gwt.dom.client.TableCellElement;
import com.google.gwt.dom.client.TableRowElement;
import com.google.gwt.dom.client.TableSectionElement;
import com.google.gwt.dom.client.Touch;
import com.google.gwt.event.dom.client.BlurEvent;
import com.google.gwt.event.dom.client.BlurHandler;
import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.event.dom.client.ScrollEvent;
import com.google.gwt.event.dom.client.ScrollHandler;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.regexp.shared.MatchResult;
import com.google.gwt.regexp.shared.RegExp;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.Event.NativePreviewEvent;
import com.google.gwt.user.client.Event.NativePreviewHandler;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HasWidgets;
import com.google.gwt.user.client.ui.Panel;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.UIObject;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.ApplicationConnection;
import com.vaadin.client.BrowserInfo;
import com.vaadin.client.ComponentConnector;
import com.vaadin.client.ConnectorMap;
import com.vaadin.client.DeferredWorker;
import com.vaadin.client.Focusable;
import com.vaadin.client.MouseEventDetailsBuilder;
import com.vaadin.client.StyleConstants;
import com.vaadin.client.TooltipInfo;
import com.vaadin.client.UIDL;
import com.vaadin.client.Util;
import com.vaadin.client.VConsole;
import com.vaadin.client.VTooltip;
import com.vaadin.client.ui.VCustomScrollTable.VScrollTableBody.VScrollTableRow;
import com.vaadin.client.ui.dd.DDUtil;
import com.vaadin.client.ui.dd.VAbstractDropHandler;
import com.vaadin.client.ui.dd.VAcceptCallback;
import com.vaadin.client.ui.dd.VDragAndDropManager;
import com.vaadin.client.ui.dd.VDragEvent;
import com.vaadin.client.ui.dd.VHasDropHandler;
import com.vaadin.client.ui.dd.VTransferable;
import com.vaadin.shared.AbstractComponentState;
import com.vaadin.shared.MouseEventDetails;
import com.vaadin.shared.ui.dd.VerticalDropLocation;
import com.vaadin.shared.ui.table.TableConstants;

/**
 * VCustomScrollTable
 * 
 * VCustomScrollTable is a FlowPanel having two widgets in it: * TableHead
 * component * ScrollPanel
 * 
 * TableHead contains table's header and widgets + logic for resizing,
 * reordering and hiding columns.
 * 
 * ScrollPanel contains VScrollTableBody object which handles content. To save
 * some bandwidth and to improve clients responsiveness with loads of data, in
 * VScrollTableBody all rows are not necessary rendered. There are "spacers" in
 * VScrollTableBody to use the exact same space as non-rendered rows would use.
 * This way we can use seamlessly traditional scrollbars and scrolling to fetch
 * more rows instead of "paging".
 * 
 * In VCustomScrollTable we listen to scroll events. On horizontal scrolling we
 * also update TableHeads scroll position which has its scrollbars hidden. On
 * vertical scroll events we will check if we are reaching the end of area where
 * we have rows rendered and
 * 
 * TODO implement unregistering for child components in Cells
 */
@SuppressWarnings("deprecation")
public class VCustomScrollTable extends FlowPanel implements HasWidgets,
        ScrollHandler, VHasDropHandler, FocusHandler, BlurHandler, Focusable,
        ActionOwner, SubPartAware, DeferredWorker {

    /**
     * Simple interface for parts of the table capable of owning a context menu.
     * 
     * @since 7.2
     * @author Vaadin Ltd
     */
    private interface ContextMenuOwner {
        public void showContextMenu(Event event);
    }

    /**
     * Handles showing context menu on "long press" from a touch screen.
     * 
     * @since 7.2
     * @author Vaadin Ltd
     */
    private class TouchContextProvider {
        private static final int TOUCH_CONTEXT_MENU_TIMEOUT = 500;
        private Timer contextTouchTimeout;

        private Event touchStart;
        private int touchStartY;
        private int touchStartX;

        private ContextMenuOwner target;

        /**
         * Initializes a handler for a certain context menu owner.
         * 
         * @param target
         *            the owner of the context menu
         */
        public TouchContextProvider(ContextMenuOwner target) {
            this.target = target;
        }

        /**
         * Cancels the current context touch timeout.
         */
        public void cancel() {
            if (contextTouchTimeout != null) {
                contextTouchTimeout.cancel();
                contextTouchTimeout = null;
            }
            touchStart = null;
        }

        /**
         * A function to handle touch context events in a table.
         * 
         * @param event
         *            browser event to handle
         */
        public void handleTouchEvent(final Event event) {
            int type = event.getTypeInt();

            switch (type) {
            case Event.ONCONTEXTMENU:
                target.showContextMenu(event);
                break;
            case Event.ONTOUCHSTART:
                // save position to fields, touches in events are same
                // instance during the operation.
                touchStart = event;

                Touch touch = event.getChangedTouches().get(0);
                touchStartX = touch.getClientX();
                touchStartY = touch.getClientY();

                if (contextTouchTimeout == null) {
                    contextTouchTimeout = new Timer() {

                        @Override
                        public void run() {
                            if (touchStart != null) {
                                // Open the context menu if finger
                                // is held in place long enough.
                                target.showContextMenu(touchStart);
                                event.preventDefault();
                                touchStart = null;
                            }
                        }
                    };
                }
                contextTouchTimeout.schedule(TOUCH_CONTEXT_MENU_TIMEOUT);
                break;
            case Event.ONTOUCHCANCEL:
            case Event.ONTOUCHEND:
                cancel();
                break;
            case Event.ONTOUCHMOVE:
                if (isSignificantMove(event)) {
                    // Moved finger before the context menu timer
                    // expired, so let the browser handle the event.
                    cancel();
                }
            }
        }

        /**
         * Calculates how many pixels away the user's finger has traveled. This
         * reduces the chance of small non-intentional movements from canceling
         * the long press detection.
         * 
         * @param event
         *            the Event for which to check the move distance
         * @return true if this is considered an intentional move by the user
         */
        protected boolean isSignificantMove(Event event) {
            if (touchStart == null) {
                // no touch start
                return false;
            }

            // Calculate the distance between touch start and the current touch
            // position
            Touch touch = event.getChangedTouches().get(0);
            int deltaX = touch.getClientX() - touchStartX;
            int deltaY = touch.getClientY() - touchStartY;
            int delta = deltaX * deltaX + deltaY * deltaY;

            // Compare to the square of the significant move threshold to remove
            // the need for a square root
            if (delta > TouchScrollDelegate.SIGNIFICANT_MOVE_THRESHOLD
                    * TouchScrollDelegate.SIGNIFICANT_MOVE_THRESHOLD) {
                return true;
            }
            return false;
        }
    }

    public static final String STYLENAME = "v-table";

    public enum SelectMode {
        NONE(0), SINGLE(1), MULTI(2);
        private int id;

        private SelectMode(int id) {
            this.id = id;
        }

        public int getId() {
            return id;
        }
    }

    private static final String ROW_HEADER_COLUMN_KEY = "0";

    private static final double CACHE_RATE_DEFAULT = 2;

    /**
     * The default multi select mode where simple left clicks only selects one
     * item, CTRL+left click selects multiple items and SHIFT-left click selects
     * a range of items.
     */
    private static final int MULTISELECT_MODE_DEFAULT = 0;

    /**
     * The simple multiselect mode is what the table used to have before
     * ctrl/shift selections were added. That is that when this is set clicking
     * on an item selects/deselects the item and no ctrl/shift selections are
     * available.
     */
    private static final int MULTISELECT_MODE_SIMPLE = 1;

    /**
     * multiple of pagelength which component will cache when requesting more
     * rows
     */
    private double cache_rate = CACHE_RATE_DEFAULT;
    /**
     * fraction of pageLenght which can be scrolled without making new request
     */
    private double cache_react_rate = 0.75 * cache_rate;

    public static final char ALIGN_CENTER = 'c';
    public static final char ALIGN_LEFT = 'b';
    public static final char ALIGN_RIGHT = 'e';
    private static final int CHARCODE_SPACE = 32;
    private int firstRowInViewPort = 0;
    private int pageLength = 15;
    private int lastRequestedFirstvisible = 0; // to detect "serverside scroll"
    private int firstvisibleOnLastPage = -1; // To detect if the first visible
                                             // is on the last page

    /** For internal use only. May be removed or replaced in the future. */
    public boolean showRowHeaders = false;

    private String[] columnOrder;

    protected ApplicationConnection client;

    /** For internal use only. May be removed or replaced in the future. */
    public String paintableId;

    /** For internal use only. May be removed or replaced in the future. */
    public boolean immediate;

    private boolean updatedReqRows = true;

    private boolean nullSelectionAllowed = true;

    private SelectMode selectMode = SelectMode.NONE;

    public final HashSet<String> selectedRowKeys = new HashSet<String>();

    /*
     * When scrolling and selecting at the same time, the selections are not in
     * sync with the server while retrieving new rows (until key is released).
     */
    private HashSet<Object> unSyncedselectionsBeforeRowFetch;

    /*
     * These are used when jumping between pages when pressing Home and End
     */

    /** For internal use only. May be removed or replaced in the future. */
    public boolean selectLastItemInNextRender = false;
    /** For internal use only. May be removed or replaced in the future. */
    public boolean selectFirstItemInNextRender = false;
    /** For internal use only. May be removed or replaced in the future. */
    public boolean focusFirstItemInNextRender = false;
    /** For internal use only. May be removed or replaced in the future. */
    public boolean focusLastItemInNextRender = false;

    /**
     * The currently focused row.
     * <p>
     * For internal use only. May be removed or replaced in the future.
     */
    public VScrollTableRow focusedRow;

    /**
     * Helper to store selection range start in when using the keyboard
     * <p>
     * For internal use only. May be removed or replaced in the future.
     */
    public VScrollTableRow selectionRangeStart;

    /**
     * Flag for notifying when the selection has changed and should be sent to
     * the server
     * <p>
     * For internal use only. May be removed or replaced in the future.
     */
    public boolean selectionChanged = false;

    /*
     * The speed (in pixels) which the scrolling scrolls vertically/horizontally
     */
    private int scrollingVelocity = 10;

    private Timer scrollingVelocityTimer = null;

    /** For internal use only. May be removed or replaced in the future. */
    public String[] bodyActionKeys;

    private boolean enableDebug = false;

    private static final boolean hasNativeTouchScrolling = BrowserInfo.get()
            .isTouchDevice()
            && !BrowserInfo.get().requiresTouchScrollDelegate();

    private Set<String> noncollapsibleColumns;

    /**
     * The last known row height used to preserve the height of a table with
     * custom row heights and a fixed page length after removing the last row
     * from the table.
     * 
     * A new VScrollTableBody instance is created every time the number of rows
     * changes causing {@link VScrollTableBody#rowHeight} to be discarded and
     * the height recalculated by {@link VScrollTableBody#getRowHeight(boolean)}
     * to avoid some rounding problems, e.g. round(2 * 19.8) / 2 = 20 but
     * round(3 * 19.8) / 3 = 19.66.
     */
    private double lastKnownRowHeight = Double.NaN;

    /**
     * Remember scroll position when getting detached to properly scroll back to
     * the location that there is data for if getting attached again.
     */
    private int detachedScrollPosition = 0;

    /**
     * Represents a select range of rows
     */
    private class SelectionRange {
        private VScrollTableRow startRow;
        private final int length;

        /**
         * Constuctor.
         */
        public SelectionRange(VScrollTableRow row1, VScrollTableRow row2) {
            VScrollTableRow endRow;
            if (row2.isBefore(row1)) {
                startRow = row2;
                endRow = row1;
            } else {
                startRow = row1;
                endRow = row2;
            }
            length = endRow.getIndex() - startRow.getIndex() + 1;
        }

        public SelectionRange(VScrollTableRow row, int length) {
            startRow = row;
            this.length = length;
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#toString()
         */

        @Override
        public String toString() {
            return startRow.getKey() + "-" + length;
        }

        private boolean inRange(VScrollTableRow row) {
            return row.getIndex() >= startRow.getIndex()
                    && row.getIndex() < startRow.getIndex() + length;
        }

        public Collection<SelectionRange> split(VScrollTableRow row) {
            assert row.isAttached();
            ArrayList<SelectionRange> ranges = new ArrayList<SelectionRange>(2);

            int endOfFirstRange = row.getIndex() - 1;
            if (endOfFirstRange >= startRow.getIndex()) {
                // create range of first part unless its length is < 1
                ranges.add(new SelectionRange(startRow, endOfFirstRange
                        - startRow.getIndex() + 1));
            }
            int startOfSecondRange = row.getIndex() + 1;
            if (getEndIndex() >= startOfSecondRange) {
                // create range of second part unless its length is < 1
                VScrollTableRow startOfRange = scrollBody
                        .getRowByRowIndex(startOfSecondRange);
                if (startOfRange != null) {
                    ranges.add(new SelectionRange(startOfRange, getEndIndex()
                            - startOfSecondRange + 1));
                }
            }
            return ranges;
        }

        private int getEndIndex() {
            return startRow.getIndex() + length - 1;
        }

    }

    private final HashSet<SelectionRange> selectedRowRanges = new HashSet<SelectionRange>();

    /** For internal use only. May be removed or replaced in the future. */
    public boolean initializedAndAttached = false;

    /**
     * Flag to indicate if a column width recalculation is needed due update.
     * <p>
     * For internal use only. May be removed or replaced in the future.
     */
    public boolean headerChangedDuringUpdate = false;

    /** For internal use only. May be removed or replaced in the future. */
    public final TableHead tHead = new TableHead();

    /** For internal use only. May be removed or replaced in the future. */
    public final TableFooter tFoot = new TableFooter();

    /** Handles context menu for table body */
    private ContextMenuOwner contextMenuOwner = new ContextMenuOwner() {

        @Override
        public void showContextMenu(Event event) {
            int left = Util.getTouchOrMouseClientX(event);
            int top = Util.getTouchOrMouseClientY(event);
            boolean menuShown = handleBodyContextMenu(left, top);
            if (menuShown) {
                event.stopPropagation();
                event.preventDefault();
            }
        }
    };

    /** Handles touch events to display a context menu for table body */
    private TouchContextProvider touchContextProvider = new TouchContextProvider(
            contextMenuOwner);

    /**
     * For internal use only. May be removed or replaced in the future.
     * 
     * Overwrites onBrowserEvent function on FocusableScrollPanel to give event
     * access to touchContextProvider. Has to be public to give TableConnector
     * access to the scrollBodyPanel field.
     * 
     * @since 7.2
     * @author Vaadin Ltd
     */
    public class FocusableScrollContextPanel extends FocusableScrollPanel {
        @Override
        public void onBrowserEvent(Event event) {
            super.onBrowserEvent(event);
            touchContextProvider.handleTouchEvent(event);
        };

        public FocusableScrollContextPanel(boolean useFakeFocusElement) {
            super(useFakeFocusElement);
        }
    }

    /** For internal use only. May be removed or replaced in the future. */
    public final FocusableScrollContextPanel scrollBodyPanel = new FocusableScrollContextPanel(
            true);

    private KeyPressHandler navKeyPressHandler = new KeyPressHandler() {

        @Override
        public void onKeyPress(KeyPressEvent keyPressEvent) {
            // This is used for Firefox only, since Firefox auto-repeat
            // works correctly only if we use a key press handler, other
            // browsers handle it correctly when using a key down handler
            if (!BrowserInfo.get().isGecko()) {
                return;
            }

            NativeEvent event = keyPressEvent.getNativeEvent();
            if (!enabled) {
                // Cancel default keyboard events on a disabled Table
                // (prevents scrolling)
                event.preventDefault();
            } else if (hasFocus) {
                // Key code in Firefox/onKeyPress is present only for
                // special keys, otherwise 0 is returned
                int keyCode = event.getKeyCode();
                if (keyCode == 0 && event.getCharCode() == ' ') {
                    // Provide a keyCode for space to be compatible with
                    // FireFox keypress event
                    keyCode = CHARCODE_SPACE;
                }

                if (handleNavigation(keyCode,
                        event.getCtrlKey() || event.getMetaKey(),
                        event.getShiftKey())) {
                    event.preventDefault();
                }

                startScrollingVelocityTimer();
            }
        }

    };

    private KeyUpHandler navKeyUpHandler = new KeyUpHandler() {

        @Override
        public void onKeyUp(KeyUpEvent keyUpEvent) {
            NativeEvent event = keyUpEvent.getNativeEvent();
            int keyCode = event.getKeyCode();

            if (!isFocusable()) {
                cancelScrollingVelocityTimer();
            } else if (isNavigationKey(keyCode)) {
                if (keyCode == getNavigationDownKey()
                        || keyCode == getNavigationUpKey()) {
                    /*
                     * in multiselect mode the server may still have value from
                     * previous page. Clear it unless doing multiselection or
                     * just moving focus.
                     */
                    if (!event.getShiftKey() && !event.getCtrlKey()) {
                        instructServerToForgetPreviousSelections();
                    }
                    sendSelectedRows();
                }
                cancelScrollingVelocityTimer();
                navKeyDown = false;
            }
        }
    };

    private KeyDownHandler navKeyDownHandler = new KeyDownHandler() {

        @Override
        public void onKeyDown(KeyDownEvent keyDownEvent) {
            NativeEvent event = keyDownEvent.getNativeEvent();
            // This is not used for Firefox
            if (BrowserInfo.get().isGecko()) {
                return;
            }

            if (!enabled) {
                // Cancel default keyboard events on a disabled Table
                // (prevents scrolling)
                event.preventDefault();
            } else if (hasFocus) {
                if (handleNavigation(event.getKeyCode(), event.getCtrlKey()
                        || event.getMetaKey(), event.getShiftKey())) {
                    navKeyDown = true;
                    event.preventDefault();
                }

                startScrollingVelocityTimer();
            }
        }
    };

    /** For internal use only. May be removed or replaced in the future. */
    public int totalRows;

    private Set<String> collapsedColumns;

    /** For internal use only. May be removed or replaced in the future. */
    public final RowRequestHandler rowRequestHandler;

    /** For internal use only. May be removed or replaced in the future. */
    public VScrollTableBody scrollBody;

    private int firstvisible = 0;
    private boolean sortAscending;
    private String sortColumn;
    private String oldSortColumn;
    private boolean columnReordering;

    /**
     * This map contains captions and icon urls for actions like: * "33_c" ->
     * "Edit" * "33_i" -> "http://dom.com/edit.png"
     */
    private final HashMap<Object, String> actionMap = new HashMap<Object, String>();
    private String[] visibleColOrder;
    private boolean initialContentReceived = false;
    private Element scrollPositionElement;

    /** For internal use only. May be removed or replaced in the future. */
    public boolean enabled;

    /** For internal use only. May be removed or replaced in the future. */
    public boolean showColHeaders;

    /** For internal use only. May be removed or replaced in the future. */
    public boolean showColFooters;

    /** flag to indicate that table body has changed */
    private boolean isNewBody = true;

    /**
     * Read from the "recalcWidths" -attribute. When it is true, the table will
     * recalculate the widths for columns - desirable in some cases. For #1983,
     * marked experimental. See also variable <code>refreshContentWidths</code>
     * in method {@link TableHead#updateCellsFromUIDL(UIDL)}.
     * <p>
     * For internal use only. May be removed or replaced in the future.
     */
    public boolean recalcWidths = false;

    /** For internal use only. May be removed or replaced in the future. */
    public boolean rendering = false;

    private boolean hasFocus = false;
    private int dragmode;

    private int multiselectmode;

    /** For internal use only. May be removed or replaced in the future. */
    public int tabIndex;

    private TouchScrollDelegate touchScrollDelegate;

    /** For internal use only. May be removed or replaced in the future. */
    public int lastRenderedHeight;

    /**
     * Values (serverCacheFirst+serverCacheLast) sent by server that tells which
     * rows (indexes) are in the server side cache (page buffer). -1 means
     * unknown. The server side cache row MUST MATCH the client side cache rows.
     * 
     * If the client side cache contains additional rows with e.g. buttons, it
     * will cause out of sync when such a button is pressed.
     * 
     * If the server side cache contains additional rows with e.g. buttons,
     * scrolling in the client will cause empty buttons to be rendered
     * (cached=true request for non-existing components)
     * 
     * For internal use only. May be removed or replaced in the future.
     */
    public int serverCacheFirst = -1;
    public int serverCacheLast = -1;

    /**
     * In several cases TreeTable depends on the scrollBody.lastRendered being
     * 'out of sync' while the update is being done. In those cases the sanity
     * check must be performed afterwards.
     */
    public boolean postponeSanityCheckForLastRendered;

    /** For internal use only. May be removed or replaced in the future. */
    public boolean sizeNeedsInit = true;

    /**
     * Used to recall the position of an open context menu if we need to close
     * and reopen it during a row update.
     * <p>
     * For internal use only. May be removed or replaced in the future.
     */
    public class ContextMenuDetails implements CloseHandler<PopupPanel> {
        public String rowKey;
        public int left;
        public int top;
        HandlerRegistration closeRegistration;

        public ContextMenuDetails(VContextMenu menu, String rowKey, int left,
                int top) {
            this.rowKey = rowKey;
            this.left = left;
            this.top = top;
            closeRegistration = menu.addCloseHandler(this);
        }

        @Override
        public void onClose(CloseEvent<PopupPanel> event) {
            contextMenu = null;
            closeRegistration.removeHandler();
        }
    }

    /** For internal use only. May be removed or replaced in the future. */
    public ContextMenuDetails contextMenu = null;

    private boolean hadScrollBars = false;

    private HandlerRegistration addCloseHandler;

    /**
     * Changes to manage mouseDown and mouseUp
     */
    /**
     * The element where the last mouse down event was registered.
     */
    private Element lastMouseDownTarget;

    /**
     * Set to true by {@link #mouseUpPreviewHandler} if it gets a mouseup at the
     * same element as {@link #lastMouseDownTarget}.
     */
    private boolean mouseUpPreviewMatched = false;

    private HandlerRegistration mouseUpEventPreviewRegistration;

    /**
     * Previews events after a mousedown to detect where the following mouseup
     * hits.
     */
    private final NativePreviewHandler mouseUpPreviewHandler = new NativePreviewHandler() {

        @Override
        public void onPreviewNativeEvent(NativePreviewEvent event) {
            if (event.getTypeInt() == Event.ONMOUSEUP) {
                mouseUpEventPreviewRegistration.removeHandler();

                // Event's reported target not always correct if event
                // capture is in use
                Element elementUnderMouse = Util.getElementUnderMouse(event
                        .getNativeEvent());
                if (lastMouseDownTarget != null
                        && lastMouseDownTarget.isOrHasChild(elementUnderMouse)) {
                    mouseUpPreviewMatched = true;
                } else {
                    getLogger().log(
                            Level.FINEST,
                            "Ignoring mouseup from " + elementUnderMouse
                                    + " when mousedown was on "
                                    + lastMouseDownTarget);
                }
            }
        }
    };

    public VCustomScrollTable() {
        setMultiSelectMode(MULTISELECT_MODE_DEFAULT);

        scrollBodyPanel.addFocusHandler(this);
        scrollBodyPanel.addBlurHandler(this);

        scrollBodyPanel.addScrollHandler(this);

        /*
         * Firefox auto-repeat works correctly only if we use a key press
         * handler, other browsers handle it correctly when using a key down
         * handler
         */
        if (BrowserInfo.get().isGecko()) {
            scrollBodyPanel.addKeyPressHandler(navKeyPressHandler);
        } else {
            scrollBodyPanel.addKeyDownHandler(navKeyDownHandler);
        }
        scrollBodyPanel.addKeyUpHandler(navKeyUpHandler);

        scrollBodyPanel.sinkEvents(Event.TOUCHEVENTS | Event.ONCONTEXTMENU);

        setStyleName(STYLENAME);

        add(tHead);
        add(scrollBodyPanel);
        add(tFoot);

        rowRequestHandler = new RowRequestHandler();
    }

    @Override
    public void setStyleName(String style) {
        updateStyleNames(style, false);
    }

    @Override
    public void setStylePrimaryName(String style) {
        updateStyleNames(style, true);
    }

    private void updateStyleNames(String newStyle, boolean isPrimary) {
        scrollBodyPanel
                .removeStyleName(getStylePrimaryName() + "-body-wrapper");
        scrollBodyPanel.removeStyleName(getStylePrimaryName() + "-body");

        if (scrollBody != null) {
            scrollBody.removeStyleName(getStylePrimaryName()
                    + "-body-noselection");
        }

        if (isPrimary) {
            super.setStylePrimaryName(newStyle);
        } else {
            super.setStyleName(newStyle);
        }

        scrollBodyPanel.addStyleName(getStylePrimaryName() + "-body-wrapper");
        scrollBodyPanel.addStyleName(getStylePrimaryName() + "-body");

        tHead.updateStyleNames(getStylePrimaryName());
        tFoot.updateStyleNames(getStylePrimaryName());

        if (scrollBody != null) {
            scrollBody.updateStyleNames(getStylePrimaryName());
        }
    }

    public void init(ApplicationConnection client) {
        this.client = client;
        // Add a handler to clear saved context menu details when the menu
        // closes. See #8526.
        addCloseHandler = client.getContextMenu().addCloseHandler(
                new CloseHandler<PopupPanel>() {

                    @Override
                    public void onClose(CloseEvent<PopupPanel> event) {
                        contextMenu = null;
                    }
                });
    }

    /**
     * Handles a context menu event on table body.
     * 
     * @param left
     *            left position of the context menu
     * @param top
     *            top position of the context menu
     * @return true if a context menu was shown, otherwise false
     */
    private boolean handleBodyContextMenu(int left, int top) {
        if (enabled && bodyActionKeys != null) {
            top += Window.getScrollTop();
            left += Window.getScrollLeft();
            client.getContextMenu().showAt(this, left, top);
            return true;
        }
        return false;
    }

    /**
     * Fires a column resize event which sends the resize information to the
     * server.
     * 
     * @param columnId
     *            The columnId of the column which was resized
     * @param originalWidth
     *            The width in pixels of the column before the resize event
     * @param newWidth
     *            The width in pixels of the column after the resize event
     */
    private void fireColumnResizeEvent(String columnId, int originalWidth,
            int newWidth) {
        client.updateVariable(paintableId, "columnResizeEventColumn", columnId,
                false);
        client.updateVariable(paintableId, "columnResizeEventPrev",
                originalWidth, false);
        client.updateVariable(paintableId, "columnResizeEventCurr", newWidth,
                immediate);

    }

    /**
     * Non-immediate variable update of column widths for a collection of
     * columns.
     * 
     * @param columns
     *            the columns to trigger the events for.
     */
    private void sendColumnWidthUpdates(Collection<HeaderCell> columns) {
        String[] newSizes = new String[columns.size()];
        int ix = 0;
        for (HeaderCell cell : columns) {
            newSizes[ix++] = cell.getColKey() + ":" + cell.getWidth();
        }
        client.updateVariable(paintableId, "columnWidthUpdates", newSizes,
                false);
    }

    /**
     * Moves the focus one step down
     * 
     * @return Returns true if succeeded
     */
    private boolean moveFocusDown() {
        return moveFocusDown(0);
    }

    /**
     * Moves the focus down by 1+offset rows
     * 
     * @return Returns true if succeeded, else false if the selection could not
     *         be move downwards
     */
    private boolean moveFocusDown(int offset) {
        if (isSelectable()) {
            if (focusedRow == null && scrollBody.iterator().hasNext()) {
                // FIXME should focus first visible from top, not first rendered
                // ??
                return setRowFocus((VScrollTableRow) scrollBody.iterator()
                        .next());
            } else {
                VScrollTableRow next = getNextRow(focusedRow, offset);
                if (next != null) {
                    return setRowFocus(next);
                }
            }
        }

        return false;
    }

    /**
     * Moves the selection one step up
     * 
     * @return Returns true if succeeded
     */
    private boolean moveFocusUp() {
        return moveFocusUp(0);
    }

    /**
     * Moves the focus row upwards
     * 
     * @return Returns true if succeeded, else false if the selection could not
     *         be move upwards
     * 
     */
    private boolean moveFocusUp(int offset) {
        if (isSelectable()) {
            if (focusedRow == null && scrollBody.iterator().hasNext()) {
                // FIXME logic is exactly the same as in moveFocusDown, should
                // be the opposite??
                return setRowFocus((VScrollTableRow) scrollBody.iterator()
                        .next());
            } else {
                VScrollTableRow prev = getPreviousRow(focusedRow, offset);
                if (prev != null) {
                    return setRowFocus(prev);
                } else {
                    VConsole.log("no previous available");
                }
            }
        }

        return false;
    }

    /**
     * Selects a row where the current selection head is
     * 
     * @param ctrlSelect
     *            Is the selection a ctrl+selection
     * @param shiftSelect
     *            Is the selection a shift+selection
     * @return Returns truw
     */
    private void selectFocusedRow(boolean ctrlSelect, boolean shiftSelect) {
        if (focusedRow != null) {
            // Arrows moves the selection and clears previous selections
            if (isSelectable() && !ctrlSelect && !shiftSelect) {
                deselectAll();
                focusedRow.toggleSelection();
                selectionRangeStart = focusedRow;
            } else if (isSelectable() && ctrlSelect && !shiftSelect) {
                // Ctrl+arrows moves selection head
                selectionRangeStart = focusedRow;
                // No selection, only selection head is moved
            } else if (isMultiSelectModeAny() && !ctrlSelect && shiftSelect) {
                // Shift+arrows selection selects a range
                focusedRow.toggleShiftSelection(shiftSelect);
            }
        }
    }

    /**
     * Sends the selection to the server if changed since the last update/visit.
     */
    protected void sendSelectedRows() {
        sendSelectedRows(immediate);
    }

    /**
     * Sends the selection to the server if it has been changed since the last
     * update/visit.
     * 
     * @param immediately
     *            set to true to immediately send the rows
     */
    protected void sendSelectedRows(boolean immediately) {
        // Don't send anything if selection has not changed
        if (!selectionChanged) {
            return;
        }

        // Reset selection changed flag
        selectionChanged = false;

        // Note: changing the immediateness of this might require changes to
        // "clickEvent" immediateness also.
        if (isMultiSelectModeDefault()) {
            // Convert ranges to a set of strings
            Set<String> ranges = new HashSet<String>();
            for (SelectionRange range : selectedRowRanges) {
                ranges.add(range.toString());
            }

            // Send the selected row ranges
            client.updateVariable(paintableId, "selectedRanges",
                    ranges.toArray(new String[selectedRowRanges.size()]), false);
            selectedRowRanges.clear();

            // clean selectedRowKeys so that they don't contain excess values
            for (Iterator<String> iterator = selectedRowKeys.iterator(); iterator
                    .hasNext();) {
                String key = iterator.next();
                VScrollTableRow renderedRowByKey = getRenderedRowByKey(key);
                if (renderedRowByKey != null) {
                    for (SelectionRange range : selectedRowRanges) {
                        if (range.inRange(renderedRowByKey)) {
                            iterator.remove();
                        }
                    }
                } else {
                    // orphaned selected key, must be in a range, ignore
                    iterator.remove();
                }

            }
        }

        // Send the selected rows
        client.updateVariable(paintableId, "selected",
                selectedRowKeys.toArray(new String[selectedRowKeys.size()]),
                immediately);

    }

    /**
     * Get the key that moves the selection head upwards. By default it is the
     * up arrow key but by overriding this you can change the key to whatever
     * you want.
     * 
     * @return The keycode of the key
     */
    protected int getNavigationUpKey() {
        return KeyCodes.KEY_UP;
    }

    /**
     * Get the key that moves the selection head downwards. By default it is the
     * down arrow key but by overriding this you can change the key to whatever
     * you want.
     * 
     * @return The keycode of the key
     */
    protected int getNavigationDownKey() {
        return KeyCodes.KEY_DOWN;
    }

    /**
     * Get the key that scrolls to the left in the table. By default it is the
     * left arrow key but by overriding this you can change the key to whatever
     * you want.
     * 
     * @return The keycode of the key
     */
    protected int getNavigationLeftKey() {
        return KeyCodes.KEY_LEFT;
    }

    /**
     * Get the key that scroll to the right on the table. By default it is the
     * right arrow key but by overriding this you can change the key to whatever
     * you want.
     * 
     * @return The keycode of the key
     */
    protected int getNavigationRightKey() {
        return KeyCodes.KEY_RIGHT;
    }

    /**
     * Get the key that selects an item in the table. By default it is the space
     * bar key but by overriding this you can change the key to whatever you
     * want.
     * 
     * @return
     */
    protected int getNavigationSelectKey() {
        return CHARCODE_SPACE;
    }

    /**
     * Get the key the moves the selection one page up in the table. By default
     * this is the Page Up key but by overriding this you can change the key to
     * whatever you want.
     * 
     * @return
     */
    protected int getNavigationPageUpKey() {
        return KeyCodes.KEY_PAGEUP;
    }

    /**
     * Get the key the moves the selection one page down in the table. By
     * default this is the Page Down key but by overriding this you can change
     * the key to whatever you want.
     * 
     * @return
     */
    protected int getNavigationPageDownKey() {
        return KeyCodes.KEY_PAGEDOWN;
    }

    /**
     * Get the key the moves the selection to the beginning of the table. By
     * default this is the Home key but by overriding this you can change the
     * key to whatever you want.
     * 
     * @return
     */
    protected int getNavigationStartKey() {
        return KeyCodes.KEY_HOME;
    }

    /**
     * Get the key the moves the selection to the end of the table. By default
     * this is the End key but by overriding this you can change the key to
     * whatever you want.
     * 
     * @return
     */
    protected int getNavigationEndKey() {
        return KeyCodes.KEY_END;
    }

    /** For internal use only. May be removed or replaced in the future. */
    public void initializeRows(UIDL uidl, UIDL rowData) {
        if (scrollBody != null) {
            scrollBody.removeFromParent();
        }

        // Without this call the scroll position is messed up in IE even after
        // the lazy scroller has set the scroll position to the first visible
        // item
        scrollBodyPanel.getScrollPosition();

        scrollBody = createScrollBody();

        scrollBody.renderInitialRows(rowData, uidl.getIntAttribute("firstrow"),
                uidl.getIntAttribute("rows"));
        scrollBodyPanel.add(scrollBody);

        // New body starts scrolled to the left, make sure the header and footer
        // are also scrolled to the left
        tHead.setHorizontalScrollPosition(0);
        tFoot.setHorizontalScrollPosition(0);

        initialContentReceived = true;
        sizeNeedsInit = true;
        scrollBody.restoreRowVisibility();
    }

    /** For internal use only. May be removed or replaced in the future. */
    public void updateColumnProperties(UIDL uidl) {
        updateColumnOrder(uidl);

        updateCollapsedColumns(uidl);

        UIDL vc = uidl.getChildByTagName("visiblecolumns");
        if (vc != null) {
            tHead.updateCellsFromUIDL(vc);
            tFoot.updateCellsFromUIDL(vc);
        }

        updateHeader(uidl.getStringArrayAttribute("vcolorder"));
        updateFooter(uidl.getStringArrayAttribute("vcolorder"));
        if (uidl.hasVariable("noncollapsiblecolumns")) {
            noncollapsibleColumns = uidl
                    .getStringArrayVariableAsSet("noncollapsiblecolumns");
        }
    }

    private void updateCollapsedColumns(UIDL uidl) {
        if (uidl.hasVariable("collapsedcolumns")) {
            tHead.setColumnCollapsingAllowed(true);
            collapsedColumns = uidl
                    .getStringArrayVariableAsSet("collapsedcolumns");
        } else {
            tHead.setColumnCollapsingAllowed(false);
        }
    }

    private void updateColumnOrder(UIDL uidl) {
        if (uidl.hasVariable("columnorder")) {
            columnReordering = true;
            columnOrder = uidl.getStringArrayVariable("columnorder");
        } else {
            columnReordering = false;
            columnOrder = null;
        }
    }

    /** For internal use only. May be removed or replaced in the future. */
    public boolean selectSelectedRows(UIDL uidl) {
        boolean keyboardSelectionOverRowFetchInProgress = false;

        if (uidl.hasVariable("selected")) {
            final Set<String> selectedKeys = uidl
                    .getStringArrayVariableAsSet("selected");
            removeUnselectedRowKeys(selectedKeys);

            if (scrollBody != null) {
                Iterator<Widget> iterator = scrollBody.iterator();
                while (iterator.hasNext()) {
                    /*
                     * Make the focus reflect to the server side state unless we
                     * are currently selecting multiple rows with keyboard.
                     */
                    VScrollTableRow row = (VScrollTableRow) iterator.next();
                    boolean selected = selectedKeys.contains(row.getKey());
                    if (!selected
                            && unSyncedselectionsBeforeRowFetch != null
                            && unSyncedselectionsBeforeRowFetch.contains(row
                                    .getKey())) {
                        selected = true;
                        keyboardSelectionOverRowFetchInProgress = true;
                    }
                    if (selected && selectedKeys.size() == 1) {
                        /*
                         * If a single item is selected, move focus to the
                         * selected row. (#10522)
                         */
                        setRowFocus(row);
                    }

                    if (selected != row.isSelected()) {
                        row.toggleSelection();

                        if (!isSingleSelectMode() && !selected) {
                            // Update selection range in case a row is
                            // unselected from the middle of a range - #8076
                            removeRowFromUnsentSelectionRanges(row);
                        }
                    }
                }

            }
        }
        unSyncedselectionsBeforeRowFetch = null;
        return keyboardSelectionOverRowFetchInProgress;
    }

    private void removeUnselectedRowKeys(final Set<String> selectedKeys) {
        List<String> unselectedKeys = new ArrayList<String>(0);
        for (String key : selectedRowKeys) {
            if (!selectedKeys.contains(key)) {
                unselectedKeys.add(key);
            }
        }
        selectedRowKeys.removeAll(unselectedKeys);
    }

    /** For internal use only. May be removed or replaced in the future. */
    public void updateSortingProperties(UIDL uidl) {
        oldSortColumn = sortColumn;
        if (uidl.hasVariable("sortascending")) {
            sortAscending = uidl.getBooleanVariable("sortascending");
            sortColumn = uidl.getStringVariable("sortcolumn");
        }
    }

    /** For internal use only. May be removed or replaced in the future. */
    public void resizeSortedColumnForSortIndicator() {
        // Force recalculation of the captionContainer element inside the header
        // cell to accomodate for the size of the sort arrow.
        HeaderCell sortedHeader = tHead.getHeaderCell(sortColumn);
        if (sortedHeader != null) {
            // Mark header as sorted now. Any earlier marking would lead to
            // columns with wrong sizes
            sortedHeader.setSorted(true);
            tHead.resizeCaptionContainer(sortedHeader);
        }
        // Also recalculate the width of the captionContainer element in the
        // previously sorted header, since this now has more room.
        HeaderCell oldSortedHeader = tHead.getHeaderCell(oldSortColumn);
        if (oldSortedHeader != null) {
            tHead.resizeCaptionContainer(oldSortedHeader);
        }
    }

    private boolean lazyScrollerIsActive;

    private void disableLazyScroller() {
        lazyScrollerIsActive = false;
        scrollBodyPanel.getElement().getStyle().clearOverflowX();
        scrollBodyPanel.getElement().getStyle().clearOverflowY();
    }

    private void enableLazyScroller() {
        Scheduler.get().scheduleDeferred(lazyScroller);
        lazyScrollerIsActive = true;
        // prevent scrolling to jump in IE11
        scrollBodyPanel.getElement().getStyle().setOverflowX(Overflow.HIDDEN);
        scrollBodyPanel.getElement().getStyle().setOverflowY(Overflow.HIDDEN);
    }

    private boolean isLazyScrollerActive() {
        return lazyScrollerIsActive;
    }

    private ScheduledCommand lazyScroller = new ScheduledCommand() {

        @Override
        public void execute() {
            if (firstvisible >= 0) {
                firstRowInViewPort = firstvisible;
                if (firstvisibleOnLastPage > -1) {
                    scrollBodyPanel
                            .setScrollPosition(measureRowHeightOffset(firstvisibleOnLastPage));
                } else {
                    scrollBodyPanel
                            .setScrollPosition(measureRowHeightOffset(firstvisible));
                }
     …

Large files files are truncated, but you can click here to view the full file