/*******************************************************************************
* Copyright (c) 2000, 2004 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.erlide.ui.internal.util;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.viewers.ColumnLayoutData;
import org.eclipse.jface.viewers.ColumnPixelData;
import org.eclipse.jface.viewers.ColumnWeightData;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ControlAdapter;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
/**
* A special composite to layout columns inside a table. The composite is needed
* since we have to layout the columns "before" the actual table gets layouted.
* Hence we can't use a normal layout manager.
*/
public class TableLayoutComposite extends Composite {
private final List<ColumnLayoutData> columns = new ArrayList<ColumnLayoutData>();
/**
* Creates a new <code>TableLayoutComposite</code>.
*/
public TableLayoutComposite(final Composite parent, final int style) {
super(parent, style);
addControlListener(new ControlAdapter() {
@Override
public void controlResized(final ControlEvent e) {
final Rectangle area = getClientArea();
final Table table = (Table) getChildren()[0];
final Point preferredSize = computeTableSize(table);
int width = area.width - 2 * table.getBorderWidth();
if (preferredSize.y > area.height) {
// Subtract the scrollbar width from the total column width
// if a vertical scrollbar will be required
final Point vBarSize = table.getVerticalBar().getSize();
width -= vBarSize.x;
}
layoutTable(table, width, area, table.getSize().x < area.width);
}
});
}
/**
* Adds a new column of data to this table layout.
*
* @param data
* the column layout data
*/
public void addColumnData(final ColumnLayoutData data) {
columns.add(data);
}
// ---- Helpers
// -------------------------------------------------------------------------------------
protected Point computeTableSize(final Table table) {
final Point result = table.computeSize(SWT.DEFAULT, SWT.DEFAULT);
int width = 0;
final int size = columns.size();
for (int i = 0; i < size; ++i) {
final ColumnLayoutData layoutData = columns.get(i);
if (layoutData instanceof ColumnPixelData) {
final ColumnPixelData col = (ColumnPixelData) layoutData;
width += col.width;
} else if (layoutData instanceof ColumnWeightData) {
final ColumnWeightData col = (ColumnWeightData) layoutData;
width += col.minimumWidth;
} else {
Assert.isTrue(false, "Unknown column layout data"); //$NON-NLS-1$
}
}
if (width > result.x) {
result.x = width;
}
return result;
}
protected void layoutTable(final Table table, final int width, final Rectangle area,
final boolean increase) {
if (width <= 1) {
return;
}
final TableColumn[] tableColumns = table.getColumns();
final int size = Math.min(columns.size(), tableColumns.length);
final int[] widths = new int[size];
int fixedWidth = 0;
int numberOfWeightColumns = 0;
int totalWeight = 0;
// First calc space occupied by fixed columns
for (int i = 0; i < size; i++) {
final ColumnLayoutData col = columns.get(i);
if (col instanceof ColumnPixelData) {
final int pixels = ((ColumnPixelData) col).width;
widths[i] = pixels;
fixedWidth += pixels;
} else if (col instanceof ColumnWeightData) {
final ColumnWeightData cw = (ColumnWeightData) col;
numberOfWeightColumns++;
// first time, use the weight specified by the column data,
// otherwise use
// the actual width as the weight
// int weight = firstTime ? cw.weight :
// tableColumns[i].getWidth();
final int weight = cw.weight;
totalWeight += weight;
} else {
Assert.isTrue(false, "Unknown column layout data"); //$NON-NLS-1$
}
}
// Do we have columns that have a weight
if (numberOfWeightColumns > 0) {
// Now distribute the rest to the columns with weight.
final int rest = width - fixedWidth;
int totalDistributed = 0;
for (int i = 0; i < size; ++i) {
final ColumnLayoutData col = columns.get(i);
if (col instanceof ColumnWeightData) {
final ColumnWeightData cw = (ColumnWeightData) col;
// calculate weight as above
// int weight = firstTime ? cw.weight :
// tableColumns[i].getWidth();
final int weight = cw.weight;
int pixels = totalWeight == 0 ? 0 : weight * rest / totalWeight;
if (pixels < cw.minimumWidth) {
pixels = cw.minimumWidth;
}
totalDistributed += pixels;
widths[i] = pixels;
}
}
// Distribute any remaining pixels to columns with weight.
int diff = rest - totalDistributed;
for (int i = 0; diff > 0; ++i) {
if (i == size) {
i = 0;
}
final ColumnLayoutData col = columns.get(i);
if (col instanceof ColumnWeightData) {
++widths[i];
--diff;
}
}
}
if (increase) {
table.setSize(area.width, area.height);
}
for (int i = 0; i < size; i++) {
tableColumns[i].setWidth(widths[i]);
}
if (!increase) {
table.setSize(area.width, area.height);
}
}
}