org.metawidget.swt.layout.GridLayout Maven / Gradle / Ivy
// Metawidget
//
// This file is dual licensed under both the LGPL
// (http://www.gnu.org/licenses/lgpl-2.1.html) and the EPL
// (http://www.eclipse.org/org/documents/epl-v10.php). As a
// recipient of Metawidget, you may choose to receive it under either
// the LGPL or the EPL.
//
// Commercial licenses are also available. See http://metawidget.org
// for details.
package org.metawidget.swt.layout;
import static org.metawidget.inspector.InspectionResultConstants.*;
import java.util.Map;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.metawidget.layout.iface.AdvancedLayout;
import org.metawidget.swt.Facet;
import org.metawidget.swt.Stub;
import org.metawidget.swt.SwtMetawidget;
import org.metawidget.util.WidgetBuilderUtils;
import org.metawidget.util.simple.SimpleLayoutUtils;
/**
* Layout to arrange widgets using org.eclipse.swt.layout.GridLayout.
*
* Widgets are arranged in a table, with one column for labels and another for the widget.
*
* @author Richard Kennard
*/
public class GridLayout
implements AdvancedLayout {
//
// Private statics
//
private static final int LABEL_AND_CONTROL = 2;
private static final String LABEL_NAME_SUFFIX = "_label";
//
// Private members
//
private final int mNumberOfColumns;
private final int mLabelAlignment;
private final Font mLabelFont;
private final Color mLabelForeground;
private final String mLabelSuffix;
private final int mRequiredAlignment;
private final String mRequiredText;
//
// Constructor
//
public GridLayout() {
this( new GridLayoutConfig() );
}
public GridLayout( GridLayoutConfig config ) {
mNumberOfColumns = config.getNumberOfColumns();
mLabelAlignment = config.getLabelAlignment();
mLabelForeground = config.getLabelForeground();
mLabelFont = config.getLabelFont();
mLabelSuffix = config.getLabelSuffix();
mRequiredAlignment = config.getRequiredAlignment();
mRequiredText = config.getRequiredText();
}
//
// Public methods
//
public void onStartBuild( SwtMetawidget metawidget ) {
// Do nothing
}
public void startContainerLayout( Composite composite, SwtMetawidget metawidget ) {
// Calculate default label inset
//
// We top align all our labels, not just those belonging to 'tall' controls,
// so that tall controls, regular controls and nested Metawidget controls all line up.
// However, we still want the JLabels to be middle aligned for one-line controls (such as
// Text boxes), so we top inset them a bit
org.eclipse.swt.layout.GridLayout layoutManager = new org.eclipse.swt.layout.GridLayout( mNumberOfColumns * LABEL_AND_CONTROL, false );
composite.setLayout( layoutManager );
// Initially (and after a 're-layout', say when they click the 'Edit' button and we
// setReadOnly( false )) none of the manually added controls should have any layout
// information. getTotalHorizontalSpan and getLastNonExcludedControl rely on this.
for ( Control control : composite.getChildren() ) {
control.setLayoutData( null );
}
}
public void layoutWidget( Control control, String elementName, Map attributes, Composite composite, SwtMetawidget metawidget ) {
// Do not layout space for empty stubs
if ( control instanceof Stub && ( (Stub) control ).getChildren().length == 0 ) {
GridData stubData = new GridData();
stubData.exclude = true;
control.setLayoutData( stubData );
return;
}
// Special support for large controls (make the previous control span all and kick us to the
// next row)
boolean spanAllColumns = willFillHorizontally( control, attributes );
if ( spanAllColumns ) {
int totalHorizontalSpan = getTotalHorizontalSpan( composite );
int numberColumnsRemainingOnRow = totalHorizontalSpan % ( mNumberOfColumns * LABEL_AND_CONTROL );
if ( numberColumnsRemainingOnRow != 0 ) {
Control lastControl = getLastNonExcludedControl( composite );
( (GridData) lastControl.getLayoutData() ).horizontalSpan = numberColumnsRemainingOnRow + 1;
}
}
// Layout a label...
String labelText = null;
if ( attributes != null ) {
labelText = metawidget.getLabelString( attributes );
}
layoutBeforeChild( control, labelText, elementName, attributes, composite, metawidget );
// ...and layout the control
GridData controlLayoutData = new GridData();
controlLayoutData.grabExcessHorizontalSpace = true;
if ( !( control instanceof Button ) ) {
controlLayoutData.horizontalAlignment = SWT.FILL;
controlLayoutData.verticalAlignment = SWT.FILL;
}
if ( spanAllColumns ) {
controlLayoutData.horizontalSpan = mNumberOfColumns * LABEL_AND_CONTROL;
if ( SimpleLayoutUtils.needsLabel( labelText, elementName ) ) {
controlLayoutData.horizontalSpan--;
}
} else if ( !SimpleLayoutUtils.needsLabel( labelText, elementName ) ) {
controlLayoutData.horizontalSpan = LABEL_AND_CONTROL;
}
if ( willFillVertically( control, attributes ) ) {
controlLayoutData.grabExcessVerticalSpace = true;
}
// Add it
control.setLayoutData( controlLayoutData );
}
public void endContainerLayout( Composite composite, SwtMetawidget metawidget ) {
// Do nothing
}
public void onEndBuild( SwtMetawidget metawidget ) {
// Buttons
Facet buttonsFacet = metawidget.getFacet( "buttons" );
if ( buttonsFacet != null ) {
GridData buttonLayoutData = new GridData();
buttonLayoutData.horizontalSpan = 2;
buttonLayoutData.horizontalAlignment = SWT.FILL;
buttonLayoutData.grabExcessHorizontalSpace = true;
buttonsFacet.setLayoutData( buttonLayoutData );
buttonsFacet.moveBelow( null );
}
}
//
// Protected methods
//
protected String layoutBeforeChild( Control control, String labelText, String elementName, Map attributes, Composite composite, SwtMetawidget metawidget ) {
// Add label
if ( SimpleLayoutUtils.needsLabel( labelText, elementName ) ) {
Label label = new Label( composite, SWT.None );
label.setData( NAME, attributes.get( NAME ) + LABEL_NAME_SUFFIX );
if ( mLabelFont != null ) {
label.setFont( mLabelFont );
}
if ( mLabelForeground != null ) {
label.setForeground( mLabelForeground );
}
label.setAlignment( mLabelAlignment );
// Required
String labelTextToUse = labelText;
if ( mRequiredText != null && TRUE.equals( attributes.get( REQUIRED ) ) && !WidgetBuilderUtils.isReadOnly( attributes ) && !metawidget.isReadOnly() ) {
if ( mRequiredAlignment == SWT.CENTER ) {
labelTextToUse += mRequiredText;
} else if ( mRequiredAlignment == SWT.LEFT ) {
labelTextToUse = mRequiredText + labelTextToUse;
}
}
if ( mLabelSuffix != null ) {
labelTextToUse += mLabelSuffix;
}
label.setText( labelTextToUse );
GridData labelLayoutData = new GridData();
labelLayoutData.horizontalAlignment = SWT.FILL;
labelLayoutData.verticalAlignment = SWT.FILL;
label.setLayoutData( labelLayoutData );
label.moveAbove( control );
}
return labelText;
}
protected boolean willFillHorizontally( Control control, Map attributes ) {
if ( control instanceof SwtMetawidget ) {
return true;
}
return SimpleLayoutUtils.isSpanAllColumns( attributes );
}
/**
* @param control
* control that may fill vertically
*/
protected boolean willFillVertically( Control control, Map attributes ) {
if ( attributes != null && TRUE.equals( attributes.get( LARGE ) ) ) {
return true;
}
return false;
}
//
// Private methods
//
/**
* @return the total GridData.horizontalSpan of all controls, except excluded controls and the
* control we are about lay out.
*/
private int getTotalHorizontalSpan( Composite composite ) {
Control[] children = composite.getChildren();
int totalHorizontalSpan = 0;
for ( int loop = 0, length = children.length - 1; loop < length; loop++ ) {
Control child = children[loop];
GridData gridData = (GridData) child.getLayoutData();
// Manually added controls, that have not been laid out yet, will have no GridData
if ( gridData == null ) {
continue;
}
// Stubs will be excluded
if ( gridData.exclude ) {
continue;
}
totalHorizontalSpan += gridData.horizontalSpan;
}
return totalHorizontalSpan;
}
/**
* @return the last control in the composite, except excluded controls and the control we are
* about lay out.
*/
private Control getLastNonExcludedControl( Composite composite ) {
Control[] children = composite.getChildren();
for ( int loop = children.length - 2; loop > 0; loop-- ) {
Control child = children[loop];
GridData gridData = (GridData) child.getLayoutData();
// Manually added controls, that have not been laid out yet, will have no GridData
if ( gridData == null ) {
continue;
}
// Stubs will be excluded
if ( !gridData.exclude ) {
return child;
}
}
return null;
}
}