/*******************************************************************************
 * Copyright (c) 2001, 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:
 *     Rational Software - initial implementation
 *******************************************************************************/
package org.eclipse.cdt.internal.ui.wizards.dialogfields;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;

import org.eclipse.core.runtime.Assert;

/**
 * Dialog field describing a group with buttons (Checkboxes, radio buttons..)
 */
public class SelectionButtonDialogFieldGroup extends DialogField {
	
	private Composite fButtonComposite;
	
	private Button[] fButtons;
	private String[] fButtonNames;
	private boolean[] fButtonsSelected;
	private boolean[] fButtonsEnabled;
	
	private int fGroupBorderStyle;
	private int fGroupNumberOfColumns;
	private int fButtonsStyle;	
		
	/**
	 * Creates a group without border.
	 */
	public SelectionButtonDialogFieldGroup(int buttonsStyle, String[] buttonNames, int nColumns) {
		this(buttonsStyle, buttonNames, nColumns, SWT.NONE);		
	}	
	
	
	/**
	 * Creates a group with border (label in border).
	 * Accepted button styles are: SWT.RADIO, SWT.CHECK, SWT.TOGGLE
	 * For border styles see <code>Group</code>
	 */	
	public SelectionButtonDialogFieldGroup(int buttonsStyle, String[] buttonNames, int nColumns, int borderStyle) {
		super();
		
		Assert.isTrue(buttonsStyle == SWT.RADIO || buttonsStyle == SWT.CHECK || buttonsStyle == SWT.TOGGLE);
		fButtonNames= buttonNames;
		
		int nButtons= buttonNames.length;
		fButtonsSelected= new boolean[nButtons];
		fButtonsEnabled= new boolean[nButtons];
		for (int i= 0; i < nButtons; i++) {
			fButtonsSelected[i]= false;
			fButtonsEnabled[i]= true;
		}
		if (fButtonsStyle == SWT.RADIO) {
			fButtonsSelected[0]= true;
		}
		
		fGroupBorderStyle= borderStyle;
		fGroupNumberOfColumns= (nColumns <= 0) ? nButtons : nColumns;
		
		fButtonsStyle= buttonsStyle;
		
	}
	
	// ------- layout helpers
		
	/*
	 * @see DialogField#doFillIntoGrid
	 */
	@Override
	public Control[] doFillIntoGrid(Composite parent, int nColumns) {
		assertEnoughColumns(nColumns);
				
		if (fGroupBorderStyle == SWT.NONE) {
			Label label= getLabelControl(parent);
			label.setLayoutData(gridDataForLabel(1));
		
			Composite buttonsgroup= getSelectionButtonsGroup(parent);
			GridData gd= new GridData();
			gd.horizontalSpan= nColumns - 1;
			buttonsgroup.setLayoutData(gd);
			
			return new Control[] { label, buttonsgroup };
		}
		Composite buttonsgroup= getSelectionButtonsGroup(parent);
		GridData gd= new GridData();
		gd.horizontalSpan= nColumns;
		buttonsgroup.setLayoutData(gd);
		
		return new Control[] { buttonsgroup };
	}	

	/*
	 * @see DialogField#doFillIntoGrid
	 */	
	@Override
	public int getNumberOfControls() {
		return (fGroupBorderStyle == SWT.NONE) ? 2 : 1;
	}
	
	// ------- ui creation
	
	private Button createSelectionButton(int index, Composite group, SelectionListener listener) {
		Button button= new Button(group, fButtonsStyle | SWT.LEFT);
		button.setFont(group.getFont());			
		button.setText(fButtonNames[index]);
		button.setEnabled(isEnabled() && fButtonsEnabled[index]);
		button.setSelection(fButtonsSelected[index]);
		button.addSelectionListener(listener);
		button.setLayoutData(new GridData());
		return button;
	}

	/**
	 * Returns the group widget. When called the first time, the widget will be created.
	 * @param parent the parent composite when called the first time, or <code>null</code>
	 * after.
	 */
	public Composite getSelectionButtonsGroup(Composite parent) {
		if (fButtonComposite == null) {
			assertCompositeNotNull(parent);
			
			GridLayout layout= new GridLayout();
			layout.makeColumnsEqualWidth= true;
			layout.numColumns= fGroupNumberOfColumns;			
			
			if (fGroupBorderStyle != SWT.NONE) {
				Group group= new Group(parent, fGroupBorderStyle);
				if (fLabelText != null && fLabelText.length() > 0) {
					group.setText(fLabelText);
				}
				fButtonComposite= group;
			} else {
				fButtonComposite= new Composite(parent, SWT.NULL);
				layout.marginHeight= 0;
				layout.marginWidth= 0;
			}

			fButtonComposite.setLayout(layout);
			
			SelectionListener listener= new SelectionListener() {
				@Override
				public void widgetDefaultSelected(SelectionEvent e) {
					doWidgetSelected(e);
				}
				@Override
				public void widgetSelected(SelectionEvent e) {
					doWidgetSelected(e);
				}
			};	
			int nButtons= fButtonNames.length;
			fButtons= new Button[nButtons]; 
			for (int i= 0; i < nButtons; i++) {
				fButtons[i]= createSelectionButton(i, fButtonComposite, listener);
			}
			int nRows= nButtons / fGroupNumberOfColumns;
			int nFillElements= nRows * fGroupNumberOfColumns - nButtons;
			for (int i= 0; i < nFillElements; i++) {
				createEmptySpace(fButtonComposite);
			}
		}
		return fButtonComposite;
	}

	/**
	 * Returns a button from the group or <code>null</code> if not yet created.
	 */	
	public Button getSelectionButton(int index) {
		if (index >= 0 && index < fButtons.length) {
			return fButtons[index];
		}
		return null;
	}
	
	protected void doWidgetSelected(SelectionEvent e) {
		Button button= (Button)e.widget;
		for (int i= 0; i < fButtons.length; i++) {
			if (fButtons[i] == button) {
				fButtonsSelected[i]= button.getSelection();
				dialogFieldChanged();
				return;
			}
		}
	}	
	
	// ------ model access	

	/**
	 * Returns the selection state of a button contained in the group.
	 * @param index the index of the button
	 */
	public boolean isSelected(int index) {
		if (index >= 0 && index < fButtonsSelected.length) {
			return fButtonsSelected[index];
		}
		return false;
	}
	
	/**
	 * Sets the selection state of a button contained in the group.
	 */
	public void setSelection(int index, boolean selected) {
		if (index >= 0 && index < fButtonsSelected.length) {
			if (fButtonsSelected[index] != selected) {
				fButtonsSelected[index]= selected;
				if (fButtons != null) {
					Button button= fButtons[index];
					if (isOkToUse(button)) {
						button.setSelection(selected);
					}
				}
			}
		}
	}

	// ------ enable / disable management
	
	@Override
	protected void updateEnableState() {
		super.updateEnableState();
		if (fButtons != null) {
			boolean enabled= isEnabled();
			for (int i= 0; i < fButtons.length; i++) {
				Button button= fButtons[i];
				if (isOkToUse(button)) {
					button.setEnabled(enabled && fButtonsEnabled[i]);
				}
			}
		}
	}
	
	/**
	 * Sets the enable state of a button contained in the group.
	 */	
	public void enableSelectionButton(int index, boolean enable) {
		if (index >= 0 && index < fButtonsEnabled.length) {
			fButtonsEnabled[index]= enable;
			if (fButtons != null) {
				Button button= fButtons[index];
				if (isOkToUse(button)) {
					button.setEnabled(isEnabled() && enable);
				}
			}
		}
	}	
}
