org.eclipse.jface.viewers.TableLayout Maven / Gradle / Ivy
/*******************************************************************************
* 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
* Florian Priester - bug 106059
*******************************************************************************/
package org.eclipse.jface.viewers;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.layout.TableColumnLayout;
import org.eclipse.jface.util.Util;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeColumn;
/**
* A layout for a table. Call addColumnData to add columns.
* The TableLayout {@link ColumnLayoutData} is only valid until the table
* is resized. To keep the proportions constant when the table is resized
* see {@link TableColumnLayout}
*/
public class TableLayout extends Layout {
/**
* 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.
*
* @since 1.0
*/
private static int COLUMN_TRIM;
static {
if (Util.isWindows()) {
COLUMN_TRIM = 4;
} else if (Util.isMac()) {
COLUMN_TRIM = 24;
} else {
COLUMN_TRIM = 3;
}
}
/**
* The list of column layout data (element type:
* ColumnLayoutData).
*/
private List columns = new ArrayList();
/**
* Indicates whether layout has yet to be called.
*/
private boolean firstTime = true;
/**
* Creates a new table layout.
*/
public TableLayout() {
}
/**
* Adds a new column of data to this table layout.
*
* @param data
* the column layout data
*/
public void addColumnData(ColumnLayoutData data) {
columns.add(data);
}
/*
* (non-Javadoc) Method declared on Layout.
*/
public Point computeSize(Composite c, int wHint, int hHint, boolean flush) {
if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT) {
return new Point(wHint, hHint);
}
Table table = (Table) c;
// To avoid recursions.
table.setLayout(null);
// Use native layout algorithm
Point result = table.computeSize(wHint, hHint, flush);
table.setLayout(this);
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;
}
/*
* (non-Javadoc) Method declared on Layout.
*/
public void layout(Composite c, boolean flush) {
// Only do initial layout. Trying to maintain proportions when resizing
// is too hard,
// causes lots of widget flicker, causes scroll bars to appear and
// occasionally stick around (on Windows),
// requires hooking column resizing as well, and may not be what the
// user wants anyway.
if (!firstTime) {
return;
}
int width = c.getClientArea().width;
// 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;
}
Item[] tableColumns = getColumns(c);
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;
}
}
}
firstTime = false;
for (int i = 0; i < size; i++) {
setWidth(tableColumns[i], widths[i]);
}
}
/**
* Set the width of the item.
*
* @param item
* @param width
*/
private void setWidth(Item item, int width) {
if (item instanceof TreeColumn) {
((TreeColumn) item).setWidth(width);
} else {
((TableColumn) item).setWidth(width);
}
}
/**
* Return the columns for the receiver.
*
* @param composite
* @return Item[]
*/
private Item[] getColumns(Composite composite) {
if (composite instanceof Tree) {
return ((Tree) composite).getColumns();
}
return ((Table) composite).getColumns();
}
}