/*******************************************************************************
* Copyright (c) 2000, 2005 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.erlide.ui.dialogs.fields;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
/**
* Base class of all dialog fields. Dialog fields manage controls together with the model,
* independed from the creation time of the widgets. - support for automated layouting. -
* enable / disable, set focus a concept of the base class.
*
* DialogField have a label.
*/
public class DialogField {
private Label fLabel;
protected String fLabelText;
private IDialogFieldListener fDialogFieldListener;
private boolean fEnabled;
public DialogField() {
fEnabled = true;
fLabel = null;
fLabelText = ""; //$NON-NLS-1$
}
/**
* Sets the label of the dialog field.
*/
public void setLabelText(final String labeltext) {
fLabelText = labeltext;
if (isOkToUse(fLabel)) {
fLabel.setText(labeltext);
}
}
// ------ change listener
/**
* Defines the listener for this dialog field.
*/
public final void setDialogFieldListener(final IDialogFieldListener listener) {
fDialogFieldListener = listener;
}
/**
* Programatical invocation of a dialog field change.
*/
public void dialogFieldChanged() {
if (fDialogFieldListener != null) {
fDialogFieldListener.dialogFieldChanged(this);
}
}
// ------- focus management
/**
* Tries to set the focus to the dialog field. Returns <code>true</code> if the dialog
* field can take focus. To be reimplemented by dialog field implementors.
*/
public boolean setFocus() {
return false;
}
/**
* Posts <code>setFocus</code> to the display event queue.
*/
public void postSetFocusOnDialogField(final Display display) {
if (display != null) {
display.asyncExec(new Runnable() {
@Override
public void run() {
setFocus();
}
});
}
}
// ------- layout helpers
/**
* Creates all controls of the dialog field and fills it to a composite. The composite
* is assumed to have <code>MGridLayout</code> as layout. The dialog field will adjust
* its controls' spans to the number of columns given. To be reimplemented by dialog
* field implementors.
*/
public Control[] doFillIntoGrid(final Composite parent, final int nColumns) {
assertEnoughColumns(nColumns);
final Label label = getLabelControl(parent);
label.setLayoutData(gridDataForLabel(nColumns));
return new Control[] { label };
}
/**
* Returns the number of columns of the dialog field. To be reimplemented by dialog
* field implementors.
*/
public int getNumberOfControls() {
return 1;
}
protected static GridData gridDataForLabel(final int span) {
final GridData gd = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
gd.horizontalSpan = span;
return gd;
}
// ------- ui creation
/**
* Creates or returns the created label widget.
*
* @param parent
* The parent composite or <code>null</code> if the widget has already been
* created.
*/
public Label getLabelControl(final Composite parent) {
if (fLabel == null) {
assertCompositeNotNull(parent);
fLabel = new Label(parent, SWT.LEFT | SWT.WRAP);
fLabel.setFont(parent.getFont());
fLabel.setEnabled(fEnabled);
if (fLabelText != null && !"".equals(fLabelText)) { //$NON-NLS-1$
fLabel.setText(fLabelText);
} else {
fLabel.setText("."); //$NON-NLS-1$
fLabel.setVisible(false);
}
}
return fLabel;
}
/**
* Creates a spacer control.
*
* @param parent
* The parent composite
*/
public static Control createEmptySpace(final Composite parent) {
return createEmptySpace(parent, 1);
}
/**
* Creates a spacer control with the given span. The composite is assumed to have
* <code>MGridLayout</code> as layout.
*
* @param parent
* The parent composite
*/
public static Control createEmptySpace(final Composite parent, final int span) {
final Label label = new Label(parent, SWT.LEFT);
final GridData gd = new GridData();
gd.horizontalAlignment = GridData.BEGINNING;
gd.grabExcessHorizontalSpace = false;
gd.horizontalSpan = span;
gd.horizontalIndent = 0;
gd.widthHint = 0;
gd.heightHint = 0;
label.setLayoutData(gd);
return label;
}
/**
* Tests is the control is not <code>null</code> and not disposed.
*/
protected final boolean isOkToUse(final Control control) {
return control != null && Display.getCurrent() != null && !control.isDisposed();
}
// --------- enable / disable management
/**
* Sets the enable state of the dialog field.
*/
public final void setEnabled(final boolean enabled) {
if (enabled != fEnabled) {
fEnabled = enabled;
updateEnableState();
}
}
/**
* Called when the enable state changed. To be extended by dialog field implementors.
*/
protected void updateEnableState() {
if (fLabel != null) {
fLabel.setEnabled(fEnabled);
}
}
/**
* Brings the UI in sync with the model. Only needed when model was changed in
* different thread whil UI was lready created.
*/
public void refresh() {
updateEnableState();
}
/**
* Gets the enable state of the dialog field.
*/
public final boolean isEnabled() {
return fEnabled;
}
protected final void assertCompositeNotNull(final Composite comp) {
// assertThat("uncreated control requested with composite null", comp,
// is(not(nullValue())));
}
protected final void assertEnoughColumns(final int nColumns) {
// assertThat("given number of columns is too small", nColumns,
// is(greaterThanOrEqualTo(getNumberOfControls())));
}
}