net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/util/TableLayoutComposite.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.ui.util;
  12
  13 import java.util.ArrayList;
  14 import java.util.List;
  15
  16 import org.eclipse.jface.util.Assert;
  17 import org.eclipse.jface.viewers.ColumnLayoutData;
  18 import org.eclipse.jface.viewers.ColumnPixelData;
  19 import org.eclipse.jface.viewers.ColumnWeightData;
  20 import org.eclipse.swt.SWT;
  21 import org.eclipse.swt.events.ControlAdapter;
  22 import org.eclipse.swt.events.ControlEvent;
  23 import org.eclipse.swt.graphics.Point;
  24 import org.eclipse.swt.graphics.Rectangle;
  25 import org.eclipse.swt.widgets.Composite;
  26 import org.eclipse.swt.widgets.Table;
  27 import org.eclipse.swt.widgets.TableColumn;
  28
  29 /**
  30  * A special composite to layout columns inside a table. The composite is needed
  31  * since we have to layout the columns "before" the actual table gets layouted.
  32  * Hence we can't use a normal layout manager.
  33  */
  34 public class TableLayoutComposite extends Composite {
  35
  36         private List columns = new ArrayList();
  37
  38         /**
  39          * Creates a new <code>TableLayoutComposite</code>.
  40          */
  41         public TableLayoutComposite(Composite parent, int style) {
  42                 super(parent, style);
  43                 addControlListener(new ControlAdapter() {
  44                         public void controlResized(ControlEvent e) {
  45                                 Rectangle area = getClientArea();
  46                                 Table table = (Table) getChildren()[0];
  47                                 Point preferredSize = computeTableSize(table);
  48                                 int width = area.width - 2 * table.getBorderWidth();
  49                                 if (preferredSize.y > area.height) {
  50                                         // Subtract the scrollbar width from the total column width
  51                                         // if a vertical scrollbar will be required
  52                                         Point vBarSize = table.getVerticalBar().getSize();
  53                                         width -= vBarSize.x;
  54                                 }
  55                                 layoutTable(table, width, area, table.getSize().x < area.width);
  56                         }
  57                 });
  58         }
  59
  60         /**
  61          * Adds a new column of data to this table layout.
  62          *
  63          * @param data
  64          *            the column layout data
  65          */
  66         public void addColumnData(ColumnLayoutData data) {
  67                 columns.add(data);
  68         }
  69
  70         // ---- Helpers
  71         // -------------------------------------------------------------------------------------
  72
  73         private Point computeTableSize(Table table) {
  74                 Point result = table.computeSize(SWT.DEFAULT, SWT.DEFAULT);
  75
  76                 int width = 0;
  77                 int size = columns.size();
  78                 for (int i = 0; i < size; ++i) {
  79                         ColumnLayoutData layoutData = (ColumnLayoutData) columns.get(i);
  80                         if (layoutData instanceof ColumnPixelData) {
  81                                 ColumnPixelData col = (ColumnPixelData) layoutData;
  82                                 width += col.width;
  83                         } else if (layoutData instanceof ColumnWeightData) {
  84                                 ColumnWeightData col = (ColumnWeightData) layoutData;
  85                                 width += col.minimumWidth;
  86                         } else {
  87                                 Assert.isTrue(false, "Unknown column layout data"); //$NON-NLS-1$
  88                         }
  89                 }
  90                 if (width > result.x)
  91                         result.x = width;
  92                 return result;
  93         }
  94
  95         private void layoutTable(Table table, int width, Rectangle area,
  96                         boolean increase) {
  97                 // XXX: Layout is being called with an invalid value the first time
  98                 // it is being called on Linux. This method resets the
  99                 // Layout to null so we make sure we run it only when
 100                 // the value is OK.
 101                 if (width <= 1)
 102                         return;
 103
 104                 TableColumn[] tableColumns = table.getColumns();
 105                 int size = Math.min(columns.size(), tableColumns.length);
 106                 int[] widths = new int[size];
 107                 int fixedWidth = 0;
 108                 int numberOfWeightColumns = 0;
 109                 int totalWeight = 0;
 110
 111                 // First calc space occupied by fixed columns
 112                 for (int i = 0; i < size; i++) {
 113                         ColumnLayoutData col = (ColumnLayoutData) columns.get(i);
 114                         if (col instanceof ColumnPixelData) {
 115                                 int pixels = ((ColumnPixelData) col).width;
 116                                 widths[i] = pixels;
 117                                 fixedWidth += pixels;
 118                         } else if (col instanceof ColumnWeightData) {
 119                                 ColumnWeightData cw = (ColumnWeightData) col;
 120                                 numberOfWeightColumns++;
 121                                 // first time, use the weight specified by the column data,
 122                                 // otherwise use the actual width as the weight
 123                                 // int weight = firstTime ? cw.weight :
 124                                 // tableColumns[i].getWidth();
 125                                 int weight = cw.weight;
 126                                 totalWeight += weight;
 127                         } else {
 128                                 Assert.isTrue(false, "Unknown column layout data"); //$NON-NLS-1$
 129                         }
 130                 }
 131
 132                 // Do we have columns that have a weight
 133                 if (numberOfWeightColumns > 0) {
 134                         // Now distribute the rest to the columns with weight.
 135                         int rest = width - fixedWidth;
 136                         int totalDistributed = 0;
 137                         for (int i = 0; i < size; ++i) {
 138                                 ColumnLayoutData col = (ColumnLayoutData) columns.get(i);
 139                                 if (col instanceof ColumnWeightData) {
 140                                         ColumnWeightData cw = (ColumnWeightData) col;
 141                                         // calculate weight as above
 142                                         // int weight = firstTime ? cw.weight :
 143                                         // tableColumns[i].getWidth();
 144                                         int weight = cw.weight;
 145                                         int pixels = totalWeight == 0 ? 0 : weight * rest
 146                                                         / totalWeight;
 147                                         if (pixels < cw.minimumWidth)
 148                                                 pixels = cw.minimumWidth;
 149                                         totalDistributed += pixels;
 150                                         widths[i] = pixels;
 151                                 }
 152                         }
 153
 154                         // Distribute any remaining pixels to columns with weight.
 155                         int diff = rest - totalDistributed;
 156                         for (int i = 0; diff > 0; ++i) {
 157                                 if (i == size)
 158                                         i = 0;
 159                                 ColumnLayoutData col = (ColumnLayoutData) columns.get(i);
 160                                 if (col instanceof ColumnWeightData) {
 161                                         ++widths[i];
 162                                         --diff;
 163                                 }
 164                         }
 165                 }
 166
 167                 if (increase) {
 168                         table.setSize(area.width, area.height);
 169                 }
 170                 for (int i = 0; i < size; i++) {
 171                         tableColumns[i].setWidth(widths[i]);
 172                 }
 173                 if (!increase) {
 174                         table.setSize(area.width, area.height);
 175                 }
 176         }
 177 }