com.netxforge.screens.editing.base.tables.FocusBlockOwnerDrawHighlighterForMultiselection.java Source code

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Here is the source code for com.netxforge.screens.editing.base.tables.FocusBlockOwnerDrawHighlighterForMultiselection.java

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/*******************************************************************************
 * Copyright (c) 6 dec. 2012 NetXForge.
 * 
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details. You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>
 * 
 * Contributors: Christophe Bouhier - initial API and implementation and/or
 * initial documentation
 *******************************************************************************/
package com.netxforge.screens.editing.base.tables;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.viewers.ColumnViewer;
import org.eclipse.jface.viewers.FocusCellOwnerDrawHighlighter;
import org.eclipse.jface.viewers.TreeViewerFocusCellManager;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.jface.viewers.ViewerRow;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;

/**
 * Hack for solving the jface Bug 268135
 * (https://bugs.eclipse.org/bugs/show_bug.cgi?id=268135) [Viewers]
 * [CellEditors] Table with SWT.MULTI and TableViewerEditor problem.
 * 
 * @see FocusCellOwnerDrawHighlighter
 */
public class FocusBlockOwnerDrawHighlighterForMultiselection extends FocusBlockHighlighter {

    /**
     * Create a new instance which can be passed to a
     * {@link TreeViewerFocusCellManager}
     * 
     * @param viewer
     *            the viewer
     */
    public FocusBlockOwnerDrawHighlighterForMultiselection(ColumnViewer viewer) {
        super(viewer);
        hookListener(viewer);
    }

    private void markFocusedBlock(Event event, List<ViewerCell> block) {

        // iterate through the cell, and draw a rectangle.
        for (ViewerCell cell : block) {
            Color background = (cell.getControl().isFocusControl()) ? getSelectedCellBackgroundColor(cell)
                    : getSelectedCellBackgroundColorNoFocus(cell);
            Color foreground = (cell.getControl().isFocusControl()) ? getSelectedCellForegroundColor(cell)
                    : getSelectedCellForegroundColorNoFocus(cell);

            if (foreground != null || background != null || onlyTextHighlighting(cell)) {
                GC gc = event.gc;

                if (background == null) {
                    background = cell.getItem().getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION);
                }

                if (foreground == null) {
                    foreground = cell.getItem().getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION_TEXT);
                }

                gc.setBackground(background);
                gc.setForeground(foreground);

                if (onlyTextHighlighting(cell)) {
                    Rectangle area = event.getBounds();
                    Rectangle rect = cell.getTextBounds();
                    if (rect != null) {
                        area.x = rect.x;
                    }
                    gc.fillRectangle(area);
                } else {
                    gc.fillRectangle(event.getBounds());

                }

            }
        }
        drawBorder(event, block);
        event.detail &= ~SWT.SELECTED;
    }

    private void drawBorder(Event event, List<ViewerCell> block) {

        Rectangle allCellsRectangle = null;

        for (ViewerCell cell : block) {
            Rectangle rect = cell.getBounds();
            if (allCellsRectangle == null) {
                allCellsRectangle = rect;
            } else {
                allCellsRectangle.add(rect);
            }
        }

        Color fg = event.gc.getForeground();
        event.gc.setForeground(event.display.getSystemColor(SWT.COLOR_BLACK));

        // Rectangle originalClipping = event.gc.getClipping();

        // Adapt the clipping, as we draw outside the bounds of the cell.
        // allCellsRectangle.x = allCellsRectangle.x - 2;
        // allCellsRectangle.y = allCellsRectangle.y - 2;
        // allCellsRectangle.height = allCellsRectangle.height + 6;
        // allCellsRectangle.width = allCellsRectangle.width + 6;

        // event.gc.setClipping(allCellsRectangle);
        event.gc.drawRoundRectangle(allCellsRectangle.x, allCellsRectangle.y, allCellsRectangle.width - 1,
                allCellsRectangle.height - 1, 3, 3);

        // event.gc.setClipping(originalClipping);
        event.gc.setForeground(fg);
    }

    private void hookListener(final ColumnViewer viewer) {
        Listener listener = new Listener() {

            public void handleEvent(Event event) {

                // System.out.println("Event index = " + event.index
                // + " coordinates = " + event.x + "," + event.y + ","
                // + event.width + "," + event.height);
                //

                if ((event.detail & SWT.SELECTED) > 0) {
                    List<ViewerCell> allCells = new ArrayList<ViewerCell>();
                    ViewerCell focusCell = getFocusCell();
                    if (focusCell != null)
                        allCells.add(focusCell);

                    // add the block to the focus cell, and mark in one go.
                    ViewerCell[] focusBlock = getFocusBlock();
                    if (focusBlock.length > 0) {
                        allCells.addAll(Arrays.asList(focusBlock));
                    }

                    if (viewer instanceof OpenTreeViewer) {
                        ViewerRow row = ((OpenTreeViewer) viewer).getViewerRowFromItemExposed(event.item);
                        Assert.isNotNull(row,
                                "Internal structure invalid. Item without associated row is not possible."); //$NON-NLS-1$

                        // Remove selection if our cell is mot in the block.
                        ViewerCell cell = row.getCell(event.index);
                        if (focusCell == null || !allCells.contains(cell)) {
                            removeSelectionInformation(event, cell);
                        } else {

                            // skip if the cell index = 0.
                            // FIXME, Should prevent focus for index = 0;
                            if (event.index > 0) {
                                markFocusedBlock(event, allCells);
                            }

                        }
                    }
                }
            }

        };
        viewer.getControl().addListener(SWT.EraseItem, listener);
    }

    /**
     * The color to use when rendering the background of the selected cell when
     * the control has the input focus
     * 
     * @param cell
     *            the cell which is colored
     * @return the color or <code>null</code> to use the default
     */
    protected Color getSelectedCellBackgroundColor(ViewerCell cell) {
        return cell.getControl().getDisplay().getSystemColor(SWT.COLOR_WHITE);
    }

    /**
     * The color to use when rendering the foreground (=text) of the selected
     * cell when the control has the input focus
     * 
     * @param cell
     *            the cell which is colored
     * @return the color or <code>null</code> to use the default
     */
    protected Color getSelectedCellForegroundColor(ViewerCell cell) {
        return cell.getControl().getDisplay().getSystemColor(SWT.COLOR_BLACK);
    }

    /**
     * The color to use when rendering the foreground (=text) of the selected
     * cell when the control has <b>no</b> input focus
     * 
     * @param cell
     *            the cell which is colored
     * @return the color or <code>null</code> to use the same used when control
     *         has focus
     * @since 3.4
     */
    protected Color getSelectedCellForegroundColorNoFocus(ViewerCell cell) {
        return null;
    }

    /**
     * The color to use when rendering the background of the selected cell when
     * the control has <b>no</b> input focus
     * 
     * @param cell
     *            the cell which is colored
     * @return the color or <code>null</code> to use the same used when control
     *         has focus
     * @since 3.4
     */
    protected Color getSelectedCellBackgroundColorNoFocus(ViewerCell cell) {
        return null;
        // return cell.getControl().getDisplay().getSystemColor(SWT.COLOR_GRAY);
    }

    /**
     * Controls whether the whole cell or only the text-area is highlighted
     * 
     * @param cell
     *            the cell which is highlighted
     * @return <code>true</code> if only the text area should be highlighted
     * @since 3.4
     */
    protected boolean onlyTextHighlighting(ViewerCell cell) {
        return false;
    }

    @Override
    protected void focusCellChanged(ViewerCell newCell, ViewerCell oldCell) {
        super.focusCellChanged(newCell, oldCell);

        // System.out
        // .println("FocusBlockOwnerDrawHighlighter => focus cell changed");

        // Redraw new area
        if (newCell != null) {
            redrawCell(newCell);
        }

        if (oldCell != null) {
            redrawCell(oldCell);
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.netxforge.netxstudio.screens.tables.FocusBlockHighlighter#
     * focusBlockChanged(org.eclipse.jface.viewers.ViewerCell[],
     * org.eclipse.jface.viewers.ViewerCell[])
     */
    @Override
    protected void focusBlockChanged(ViewerCell[] newBlock, ViewerCell[] oldBlock) {
        super.focusBlockChanged(newBlock, oldBlock);

        // Fire only what update on the viewer.

        if (newBlock != null) {
            for (ViewerCell cell : newBlock) {
                redrawCell(cell);
            }
        }
        if (oldBlock != null) {
            for (ViewerCell cell : oldBlock) {
                redrawCell(cell);
            }
        }
    }

    private void redrawCell(ViewerCell redrawCell) {
        Rectangle rect = redrawCell.getBounds();

        int x = redrawCell.getColumnIndex() == 0 ? 0 : rect.x;
        int width = redrawCell.getColumnIndex() == 0 ? rect.x + rect.width : rect.width;

        // int y = (rect.y + 1);
        // System.out.println("redraw viewercell horizontal from " + x + " to "
        // + (x + width));
        // System.out.println("redraw viewercell vertical from " + y + " to "
        // + (y + rect.height));

        // 1 is a fix for Linux-GTK
        redrawCell.getControl().redraw(x, rect.y - 1, width, rect.height + 1, true);
    }

    private void removeSelectionInformation(Event event, ViewerCell cell) {
        GC gc = event.gc;
        gc.setBackground(getUnselectedCellBackgroundColor(cell));
        gc.setForeground(getUnselectedCellForegroundColor(cell));
        gc.fillRectangle(cell.getBounds());

        event.detail &= ~SWT.SELECTED;
    }

    private Color getUnselectedCellForegroundColor(ViewerCell cell) {
        return cell.getControl().getDisplay().getSystemColor(SWT.COLOR_BLACK);
    }

    private Color getUnselectedCellBackgroundColor(ViewerCell cell) {
        return cell.getControl().getDisplay().getSystemColor(SWT.COLOR_LIST_SELECTION);
    }

}