package com.onpositive.mapper.newwizard;
import java.util.ArrayList;
import java.util.List;
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 org.eclipse.core.runtime.Assert;
import org.eclipse.jface.viewers.ColumnLayoutData;
import org.eclipse.jface.viewers.ColumnPixelData;
import org.eclipse.jface.viewers.ColumnWeightData;
/**
* 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.
* <p>
* XXX: Should switch to use {@link org.eclipse.jface.layout.TableColumnLayout}.
* </p>
*/
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.
* <p>
* XXX: Should either switch to use {@link org.eclipse.jface.layout.TableColumnLayout} or get API from JFace or SWT, see: https://bugs.eclipse.org/bugs/show_bug.cgi?id=218483
* </p>
*
* @since 3.1
*/
private static int COLUMN_TRIM;
static {
String platform = SWT.getPlatform();
if ("win32".equals(platform)) //$NON-NLS-1$
COLUMN_TRIM = 4;
else if ("carbon".equals(platform)) //$NON-NLS-1$
COLUMN_TRIM = 24;
else
COLUMN_TRIM = 3;
}
private List<ColumnLayoutData> columns = new ArrayList<ColumnLayoutData>();
/**
* Creates a new <code>TableLayoutComposite</code>.
*
* @param parent the parent composite
* @param style the SWT style
*/
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);
}
}
}