/*
* Copyright (c) 2011, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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.google.dart.tools.ui.internal.util;
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;
import java.util.ArrayList;
import java.util.List;
/**
* 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<ColumnLayoutData> columns = new ArrayList<ColumnLayoutData>();
/**
* Creates a new <code>TableLayoutComposite</code>.
*/
public TableLayoutComposite(Composite parent, int style) {
super(parent, style);
addControlListener(new ControlAdapter() {
@Override
public void controlResized(ControlEvent e) {
Rectangle area = getClientArea();
Table table = (Table) getChildren()[0];
Point preferredSize = computeTableSize(table);
int width = area.width - 2 * table.getBorderWidth();
// TODO(scheglov) by some reason I always had horizontal scrolling, so reduce width
width -= 2;
// Subtract the scrollbar width from the total column width
// if a vertical scrollbar will be required
if (preferredSize.y > area.height) {
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 = 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 = 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 = 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 = 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);
}
}
}