/*******************************************************************************
* 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.swt.layout;
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.Control;
import org.eclipse.swt.widgets.Layout;
/**
* Instances of this class determine the size and position of the
* children of a <code>Composite</code> by placing them either in
* horizontal rows or vertical columns within the parent <code>Composite</code>.
* <p>
* <code>RowLayout</code> aligns all controls in one row if the
* <code>type</code> is set to horizontal, and one column if it is
* set to vertical. It has the ability to wrap, and provides configurable
* margins and spacing. <code>RowLayout</code> has a number of configuration
* fields. In addition, the height and width of each control in a
* <code>RowLayout</code> can be specified by setting a <code>RowData</code>
* object into the control using <code>setLayoutData ()</code>.
* </p>
* <p>
* The following example code creates a <code>RowLayout</code>, sets all
* of its fields to non-default values, and then sets it into a
* <code>Shell</code>.
* <pre>
* RowLayout rowLayout = new RowLayout();
* rowLayout.wrap = false;
* rowLayout.pack = false;
* rowLayout.justify = true;
* rowLayout.type = SWT.VERTICAL;
* rowLayout.marginLeft = 5;
* rowLayout.marginTop = 5;
* rowLayout.marginRight = 5;
* rowLayout.marginBottom = 5;
* rowLayout.spacing = 0;
* shell.setLayout(rowLayout);
* </pre>
* If you are using the default field values, you only need one line of code:
* <pre>
* shell.setLayout(new RowLayout());
* </pre>
* </p>
*
* @see RowData
* @see <a href="http://www.eclipse.org/swt/snippets/#rowlayout">RowLayout snippets</a>
* @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: LayoutExample</a>
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
* @since 1.0
*/
public final class RowLayout extends Layout {
/**
* type specifies whether the layout places controls in rows or
* columns.
*
* The default value is HORIZONTAL.
*
* Possible values are: <ul>
* <li>HORIZONTAL: Position the controls horizontally from left to right</li>
* <li>VERTICAL: Position the controls vertically from top to bottom</li>
* </ul>
*/
public int type = SWT.HORIZONTAL;
/**
* marginWidth specifies the number of pixels of horizontal margin
* that will be placed along the left and right edges of the layout.
*
* The default value is 0.
*/
public int marginWidth = 0;
/**
* marginHeight specifies the number of pixels of vertical margin
* that will be placed along the top and bottom edges of the layout.
*
* The default value is 0.
*/
public int marginHeight = 0;
/**
* spacing specifies the number of pixels between the edge of one cell
* and the edge of its neighbouring cell.
*
* The default value is 3.
*/
public int spacing = 3;
/**
* wrap specifies whether a control will be wrapped to the next
* row if there is insufficient space on the current row.
*
* The default value is true.
*/
public boolean wrap = true;
/**
* pack specifies whether all controls in the layout take
* their preferred size. If pack is false, all controls will
* have the same size which is the size required to accommodate the
* largest preferred height and the largest preferred width of all
* the controls in the layout.
*
* The default value is true.
*/
public boolean pack = true;
/**
* fill specifies whether the controls in a row should be
* all the same height for horizontal layouts, or the same
* width for vertical layouts.
*
* The default value is false.
*/
public boolean fill = false;
/**
* center specifies whether the controls in a row should be
* centered vertically in each cell for horizontal layouts,
* or centered horizontally in each cell for vertical layouts.
*
* The default value is false.
*
* @since 1.2
*/
public boolean center = false;
/**
* justify specifies whether the controls in a row should be
* fully justified, with any extra space placed between the controls.
*
* The default value is false.
*/
public boolean justify = false;
/**
* marginLeft specifies the number of pixels of horizontal margin
* that will be placed along the left edge of the layout.
*
* The default value is 3.
*/
public int marginLeft = 3;
/**
* marginTop specifies the number of pixels of vertical margin
* that will be placed along the top edge of the layout.
*
* The default value is 3.
*/
public int marginTop = 3;
/**
* marginRight specifies the number of pixels of horizontal margin
* that will be placed along the right edge of the layout.
*
* The default value is 3.
*/
public int marginRight = 3;
/**
* marginBottom specifies the number of pixels of vertical margin
* that will be placed along the bottom edge of the layout.
*
* The default value is 3.
*/
public int marginBottom = 3;
/**
* Constructs a new instance of this class.
*/
public RowLayout () {
}
/**
* Constructs a new instance of this class given the type.
*
* @param type the type of row layout
*/
public RowLayout (int type) {
this.type = type;
}
protected Point computeSize (Composite composite, int wHint, int hHint, boolean flushCache) {
Point extent;
if (type == SWT.HORIZONTAL) {
extent = layoutHorizontal (composite, false, (wHint != SWT.DEFAULT) && wrap, wHint, flushCache);
} else {
extent = layoutVertical (composite, false, (hHint != SWT.DEFAULT) && wrap, hHint, flushCache);
}
if (wHint != SWT.DEFAULT) extent.x = wHint;
if (hHint != SWT.DEFAULT) extent.y = hHint;
return extent;
}
Point computeSize (Control control, boolean flushCache) {
int wHint = SWT.DEFAULT, hHint = SWT.DEFAULT;
RowData data = (RowData) control.getLayoutData ();
if (data != null) {
wHint = data.width;
hHint = data.height;
}
return control.computeSize (wHint, hHint, flushCache);
}
protected boolean flushCache (Control control) {
return true;
}
String getName () {
String string = getClass ().getName ();
int index = string.lastIndexOf ('.');
if (index == -1) return string;
return string.substring (index + 1, string.length ());
}
protected void layout (Composite composite, boolean flushCache) {
Rectangle clientArea = composite.getClientArea ();
if (type == SWT.HORIZONTAL) {
layoutHorizontal (composite, true, wrap, clientArea.width, flushCache);
} else {
layoutVertical (composite, true, wrap, clientArea.height, flushCache);
}
}
Point layoutHorizontal (Composite composite, boolean move, boolean wrap, int width, boolean flushCache) {
Control [] children = composite.getChildren ();
int count = 0;
for (int i=0; i<children.length; i++) {
Control control = children [i];
RowData data = (RowData) control.getLayoutData ();
if (data == null || !data.exclude) {
children [count++] = children [i];
}
}
if (count == 0) {
return new Point (marginLeft + marginWidth * 2 + marginRight, marginTop + marginHeight * 2 + marginBottom);
}
int childWidth = 0, childHeight = 0, maxHeight = 0;
if (!pack) {
for (int i=0; i<count; i++) {
Control child = children [i];
Point size = computeSize (child, flushCache);
childWidth = Math.max (childWidth, size.x);
childHeight = Math.max (childHeight, size.y);
}
maxHeight = childHeight;
}
int clientX = 0, clientY = 0;
if (move) {
Rectangle rect = composite.getClientArea ();
clientX = rect.x;
clientY = rect.y;
}
int [] wraps = null;
boolean wrapped = false;
Rectangle [] bounds = null;
if (move && (justify || fill || center)) {
bounds = new Rectangle [count];
wraps = new int [count];
}
int maxX = 0, x = marginLeft + marginWidth, y = marginTop + marginHeight;
for (int i=0; i<count; i++) {
Control child = children [i];
if (pack) {
Point size = computeSize (child, flushCache);
childWidth = size.x;
childHeight = size.y;
}
if (wrap && (i != 0) && (x + childWidth > width)) {
wrapped = true;
if (move && (justify || fill || center)) wraps [i - 1] = maxHeight;
x = marginLeft + marginWidth;
y += spacing + maxHeight;
if (pack) maxHeight = 0;
}
if (pack || fill || center) {
maxHeight = Math.max (maxHeight, childHeight);
}
if (move) {
int childX = x + clientX, childY = y + clientY;
if (justify || fill || center) {
bounds [i] = new Rectangle (childX, childY, childWidth, childHeight);
} else {
child.setBounds (childX, childY, childWidth, childHeight);
}
}
x += spacing + childWidth;
maxX = Math.max (maxX, x);
}
maxX = Math.max (clientX + marginLeft + marginWidth, maxX - spacing);
if (!wrapped) maxX += marginRight + marginWidth;
if (move && (justify || fill || center)) {
int space = 0, margin = 0;
if (!wrapped) {
space = Math.max (0, (width - maxX) / (count + 1));
margin = Math.max (0, ((width - maxX) % (count + 1)) / 2);
} else {
if (fill || justify || center) {
int last = 0;
if (count > 0) wraps [count - 1] = maxHeight;
for (int i=0; i<count; i++) {
if (wraps [i] != 0) {
int wrapCount = i - last + 1;
if (justify) {
int wrapX = 0;
for (int j=last; j<=i; j++) {
wrapX += bounds [j].width + spacing;
}
space = Math.max (0, (width - wrapX) / (wrapCount + 1));
margin = Math.max (0, ((width - wrapX) % (wrapCount + 1)) / 2);
}
for (int j=last; j<=i; j++) {
if (justify) bounds [j].x += (space * (j - last + 1)) + margin;
if (fill) {
bounds [j].height = wraps [i];
} else {
if (center) {
bounds [j].y += Math.max (0, (wraps [i] - bounds [j].height) / 2);
}
}
}
last = i + 1;
}
}
}
}
for (int i=0; i<count; i++) {
if (!wrapped) {
if (justify) bounds [i].x += (space * (i + 1)) + margin;
if (fill) {
bounds [i].height = maxHeight;
} else {
if (center) {
bounds [i].y += Math.max (0, (maxHeight - bounds [i].height) / 2);
}
}
}
children [i].setBounds (bounds [i]);
}
}
return new Point (maxX, y + maxHeight + marginBottom + marginHeight);
}
Point layoutVertical (Composite composite, boolean move, boolean wrap, int height, boolean flushCache) {
Control [] children = composite.getChildren ();
int count = 0;
for (int i=0; i<children.length; i++) {
Control control = children [i];
RowData data = (RowData) control.getLayoutData ();
if (data == null || !data.exclude) {
children [count++] = children [i];
}
}
if (count == 0) {
return new Point (marginLeft + marginWidth * 2 + marginRight, marginTop + marginHeight * 2 + marginBottom);
}
int childWidth = 0, childHeight = 0, maxWidth = 0;
if (!pack) {
for (int i=0; i<count; i++) {
Control child = children [i];
Point size = computeSize (child, flushCache);
childWidth = Math.max (childWidth, size.x);
childHeight = Math.max (childHeight, size.y);
}
maxWidth = childWidth;
}
int clientX = 0, clientY = 0;
if (move) {
Rectangle rect = composite.getClientArea ();
clientX = rect.x;
clientY = rect.y;
}
int [] wraps = null;
boolean wrapped = false;
Rectangle [] bounds = null;
if (move && (justify || fill || center)) {
bounds = new Rectangle [count];
wraps = new int [count];
}
int maxY = 0, x = marginLeft + marginWidth, y = marginTop + marginHeight;
for (int i=0; i<count; i++) {
Control child = children [i];
if (pack) {
Point size = computeSize (child, flushCache);
childWidth = size.x;
childHeight = size.y;
}
if (wrap && (i != 0) && (y + childHeight > height)) {
wrapped = true;
if (move && (justify || fill || center)) wraps [i - 1] = maxWidth;
x += spacing + maxWidth;
y = marginTop + marginHeight;
if (pack) maxWidth = 0;
}
if (pack || fill || center) {
maxWidth = Math.max (maxWidth, childWidth);
}
if (move) {
int childX = x + clientX, childY = y + clientY;
if (justify || fill || center) {
bounds [i] = new Rectangle (childX, childY, childWidth, childHeight);
} else {
child.setBounds (childX, childY, childWidth, childHeight);
}
}
y += spacing + childHeight;
maxY = Math.max (maxY, y);
}
maxY = Math.max (clientY + marginTop + marginHeight, maxY - spacing);
if (!wrapped) maxY += marginBottom + marginHeight;
if (move && (justify || fill || center)) {
int space = 0, margin = 0;
if (!wrapped) {
space = Math.max (0, (height - maxY) / (count + 1));
margin = Math.max (0, ((height - maxY) % (count + 1)) / 2);
} else {
if (fill || justify || center) {
int last = 0;
if (count > 0) wraps [count - 1] = maxWidth;
for (int i=0; i<count; i++) {
if (wraps [i] != 0) {
int wrapCount = i - last + 1;
if (justify) {
int wrapY = 0;
for (int j=last; j<=i; j++) {
wrapY += bounds [j].height + spacing;
}
space = Math.max (0, (height - wrapY) / (wrapCount + 1));
margin = Math.max (0, ((height - wrapY) % (wrapCount + 1)) / 2);
}
for (int j=last; j<=i; j++) {
if (justify) bounds [j].y += (space * (j - last + 1)) + margin;
if (fill) {
bounds [j].width = wraps [i];
} else {
if (center) {
bounds [j].x += Math.max (0, (wraps [i] - bounds [j].width) / 2);
}
}
}
last = i + 1;
}
}
}
}
for (int i=0; i<count; i++) {
if (!wrapped) {
if (justify) bounds [i].y += (space * (i + 1)) + margin;
if (fill) {
bounds [i].width = maxWidth;
} else {
if (center) {
bounds [i].x += Math.max (0, (maxWidth - bounds [i].width) / 2);
}
}
}
children [i].setBounds (bounds [i]);
}
}
return new Point (x + maxWidth + marginRight + marginWidth, maxY);
}
/**
* Returns a string containing a concise, human-readable
* description of the receiver.
*
* @return a string representation of the layout
*/
public String toString () {
String string = getName ()+" {";
string += "type="+((type != SWT.HORIZONTAL) ? "SWT.VERTICAL" : "SWT.HORIZONTAL")+" ";
if (marginWidth != 0) string += "marginWidth="+marginWidth+" ";
if (marginHeight != 0) string += "marginHeight="+marginHeight+" ";
if (marginLeft != 0) string += "marginLeft="+marginLeft+" ";
if (marginTop != 0) string += "marginTop="+marginTop+" ";
if (marginRight != 0) string += "marginRight="+marginRight+" ";
if (marginBottom != 0) string += "marginBottom="+marginBottom+" ";
if (spacing != 0) string += "spacing="+spacing+" ";
string += "wrap="+wrap+" ";
string += "pack="+pack+" ";
string += "fill="+fill+" ";
string += "justify="+justify+" ";
string = string.trim();
string += "}";
return string;
}
}