/*******************************************************************************
* Copyright (c) 2000, 2008 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.eclipse.wst.jsdt.internal.ui.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 {
/**
* The number of extra pixels taken as horizontal trim by the table column.
* To ensure there are N pixels available for the content of the column,
* assign N+COLUMN_TRIM for the column width.
*
*
*/
private static int COLUMN_TRIM = "carbon".equals(SWT.getPlatform()) ? 24 : 3; //$NON-NLS-1$
private List columns= new ArrayList();
/**
* Creates a new <code>TableLayoutComposite</code>.
*/
public TableLayoutComposite(Composite parent, int style) {
super(parent, style);
addControlListener(new ControlAdapter() {
public void controlResized(ControlEvent e) {
Rectangle area= getClientArea();
Table table= (Table)getChildren()[0];
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
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(ColumnLayoutData data) {
columns.add(data);
}
//---- Helpers -------------------------------------------------------------------------------------
private Point computeTableSize(Table table) {
Point result= table.computeSize(SWT.DEFAULT, SWT.DEFAULT);
int width= 0;
int size= columns.size();
for (int i= 0; i < size; ++i) {
ColumnLayoutData layoutData= (ColumnLayoutData) columns.get(i);
if (layoutData instanceof ColumnPixelData) {
ColumnPixelData col= (ColumnPixelData) layoutData;
width += col.width;
if (col.addTrim) {
width += COLUMN_TRIM;
}
} else if (layoutData instanceof ColumnWeightData) {
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;
}
private void layoutTable(Table table, int width, Rectangle area, boolean increase) {
// XXX: Layout is being called with an invalid value the first time
// it is being called on Linux. This method resets the
// Layout to null so we make sure we run it only when
// the value is OK.
if (width <= 1)
return;
TableColumn[] tableColumns= table.getColumns();
int size= Math.min(columns.size(), tableColumns.length);
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++) {
ColumnLayoutData col= (ColumnLayoutData) columns.get(i);
if (col instanceof ColumnPixelData) {
ColumnPixelData cpd= (ColumnPixelData) col;
int pixels= cpd.width;
if (cpd.addTrim) {
pixels += COLUMN_TRIM;
}
widths[i]= pixels;
fixedWidth += pixels;
} else if (col instanceof ColumnWeightData) {
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();
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.
int rest= width - fixedWidth;
int totalDistributed= 0;
for (int i= 0; i < size; ++i) {
ColumnLayoutData col= (ColumnLayoutData) columns.get(i);
if (col instanceof ColumnWeightData) {
ColumnWeightData cw= (ColumnWeightData) col;
// calculate weight as above
// int weight = firstTime ? cw.weight : tableColumns[i].getWidth();
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;
ColumnLayoutData col= (ColumnLayoutData) 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);
}
}
}