/*******************************************************************************
* Copyright (c) 2006, 2009 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 (original file org.eclipse.ui.texteditor.templates.ColumnLayout)
* Tom Schindl <tom.schindl@bestsolution.at> - refactored to be widget independent (bug 171824)
* - fix for bug 178280, 184342, 184045, 208014, 214532
* Micah Hainline <micah_hainline@yahoo.com> - fix in bug: 208335
*******************************************************************************/
package org.eclipse.jface.layout;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.util.Policy;
import org.eclipse.jface.util.Util;
import org.eclipse.jface.viewers.ColumnLayoutData;
import org.eclipse.jface.viewers.ColumnPixelData;
import org.eclipse.jface.viewers.ColumnWeightData;
import org.eclipse.jface.viewers.TableLayout;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Scrollable;
import org.eclipse.swt.widgets.Widget;
/**
* The AbstractColumnLayout is a {@link Layout} used to set the size of a table
* in a consistent way even during a resize unlike a {@link TableLayout} which
* only sets initial sizes.
*
* <p>
* <b>You can only add the layout to a container whose only child is the
* table/tree control you want the layouts applied to.</b>
* </p>
*
* @since 3.4
*/
public abstract class AbstractColumnLayout extends Layout {
private static int COLUMN_TRIM;
static {
if (Util.isWindows()) {
COLUMN_TRIM = 4;
} else if (Util.isMac()) {
COLUMN_TRIM = 24;
} else {
COLUMN_TRIM = 3;
}
}
static final boolean IS_GTK = Util.isGtk();
/**
* Key used to restore the layout data in the columns data-slot
* @since 3.5
*/
protected static final String LAYOUT_DATA = Policy.JFACE + ".LAYOUT_DATA"; //$NON-NLS-1$
private boolean inupdateMode = false;
private boolean relayout = true;
private Listener resizeListener = new Listener() {
public void handleEvent(Event event) {
if (!inupdateMode) {
updateColumnData(event.widget);
}
}
};
/**
* Adds a new column of data to this table layout.
*
* @param column
* the column
*
* @param data
* the column layout data
*/
public void setColumnData(Widget column, ColumnLayoutData data) {
if (column.getData(LAYOUT_DATA) == null) {
column.addListener(SWT.Resize, resizeListener);
}
column.setData(LAYOUT_DATA, data);
}
/**
* Compute the size of the table or tree based on the ColumnLayoutData and
* the width and height hint.
*
* @param scrollable
* the widget to compute
* @param wHint
* the width hint
* @param hHint
* the height hint
* @return Point where x is the width and y is the height
*/
private Point computeTableTreeSize(Scrollable scrollable, int wHint,
int hHint) {
Point result = scrollable.computeSize(wHint, hHint);
int width = 0;
int size = getColumnCount(scrollable);
for (int i = 0; i < size; ++i) {
ColumnLayoutData layoutData = getLayoutData(scrollable, i);
if (layoutData instanceof ColumnPixelData) {
ColumnPixelData col = (ColumnPixelData) layoutData;
width += col.width;
if (col.addTrim) {
width += getColumnTrim();
}
} 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;
}
/**
* Layout the scrollable based on the supplied width and area. Only increase
* the size of the scrollable if increase is <code>true</code>.
*
* @param scrollable
* @param width
* @param area
* @param increase
*/
private void layoutTableTree(final Scrollable scrollable, final int width,
final Rectangle area, final boolean increase) {
final int numberOfColumns = getColumnCount(scrollable);
final int[] widths = new int[numberOfColumns];
final int[] weightColumnIndices = new int[numberOfColumns];
int numberOfWeightColumns = 0;
int fixedWidth = 0;
int totalWeight = 0;
// First calc space occupied by fixed columns
for (int i = 0; i < numberOfColumns; i++) {
ColumnLayoutData col = getLayoutData(scrollable, i);
if (col instanceof ColumnPixelData) {
ColumnPixelData cpd = (ColumnPixelData) col;
int pixels = cpd.width;
if (cpd.addTrim) {
pixels += getColumnTrim();
}
widths[i] = pixels;
fixedWidth += pixels;
} else if (col instanceof ColumnWeightData) {
ColumnWeightData cw = (ColumnWeightData) col;
weightColumnIndices[numberOfWeightColumns] = i;
numberOfWeightColumns++;
totalWeight += cw.weight;
} else {
Assert.isTrue(false, "Unknown column layout data"); //$NON-NLS-1$
}
}
boolean recalculate;
do {
recalculate = false;
for (int i = 0; i < numberOfWeightColumns; i++) {
int colIndex = weightColumnIndices[i];
ColumnWeightData cw = (ColumnWeightData) getLayoutData(
scrollable, colIndex);
final int minWidth = cw.minimumWidth;
final int allowedWidth = totalWeight == 0 ? 0
: (width - fixedWidth) * cw.weight / totalWeight;
if (allowedWidth < minWidth) {
/*
* if the width assigned by weight is less than the minimum,
* then treat this column as fixed, remove it from weight
* calculations, and recalculate other weights.
*/
numberOfWeightColumns--;
totalWeight -= cw.weight;
fixedWidth += minWidth;
widths[colIndex] = minWidth;
System.arraycopy(weightColumnIndices, i + 1,
weightColumnIndices, i, numberOfWeightColumns - i);
recalculate = true;
break;
}
widths[colIndex] = allowedWidth;
}
} while (recalculate);
if (increase) {
scrollable.setSize(area.width, area.height);
}
inupdateMode = true;
setColumnWidths(scrollable, widths);
scrollable.update();
inupdateMode = false;
if (!increase) {
scrollable.setSize(area.width, area.height);
}
}
/*
* (non-Javadoc)
*
* @see
* org.eclipse.swt.widgets.Layout#computeSize(org.eclipse.swt.widgets.Composite
* , int, int, boolean)
*/
protected Point computeSize(Composite composite, int wHint, int hHint,
boolean flushCache) {
return computeTableTreeSize(getControl(composite), wHint, hHint);
}
/*
* (non-Javadoc)
*
* @see
* org.eclipse.swt.widgets.Layout#layout(org.eclipse.swt.widgets.Composite,
* boolean)
*/
protected void layout(Composite composite, boolean flushCache) {
Rectangle area = composite.getClientArea();
Scrollable table = getControl(composite);
int tableWidth = table.getSize().x;
int trim = computeTrim(area, table, tableWidth);
int width = Math.max(0, area.width - trim);
if (width > 1)
layoutTableTree(table, width, area, tableWidth < area.width);
// For the first time we need to relayout because Scrollbars are not
// calculate appropriately
if (relayout) {
relayout = false;
composite.layout();
}
}
/**
* Compute the area required for trim.
*
* @param area
* @param scrollable
* @param currentWidth
* @return int
*/
private int computeTrim(Rectangle area, Scrollable scrollable,
int currentWidth) {
int trim;
if (currentWidth > 1) {
trim = currentWidth - scrollable.getClientArea().width;
} else {
// initially, the table has no extend and no client area - use the
// border with
// plus some padding as educated guess
trim = 2 * scrollable.getBorderWidth() + 1;
}
return trim;
}
/**
* Get the control being laid out.
*
* @param composite
* the composite with the layout
* @return {@link Scrollable}
*/
Scrollable getControl(Composite composite) {
return (Scrollable) composite.getChildren()[0];
}
/**
* Get the number of columns for the receiver.
*
* @param tableTree
* the control
*
* @return the number of columns
* @since 3.5
*/
protected abstract int getColumnCount(Scrollable tableTree);
/**
* Set the widths of the columns.
*
* @param tableTree
* the control
*
* @param widths
* the widths of the column
* @since 3.5
*/
protected abstract void setColumnWidths(Scrollable tableTree, int[] widths);
/**
* Get the layout data for a column
*
* @param tableTree
* the control
* @param columnIndex
* the column index
* @return the layout data, might <b>not</b> null
* @since 3.5
*/
protected abstract ColumnLayoutData getLayoutData(Scrollable tableTree,
int columnIndex);
/**
* Update the layout data for a column
*
* @param column
* the column
* @since 3.5
*/
protected abstract void updateColumnData(Widget column);
/**
* 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.
*
* @return the trim used by the columns
* @since 3.4
*/
protected int getColumnTrim() {
return COLUMN_TRIM;
}
}