/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.text;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Drawable;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.internal.text.html.HTMLTextPresenter;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.Geometry;


/**
 * Default implementation of {@link org.eclipse.jface.text.IInformationControl}.
 * <p>
 * Displays textual information in a {@link org.eclipse.swt.custom.StyledText} widget. Before
 * displaying, the information set to this information control is processed by an
 * <code>IInformationPresenter</code>.
 * </p>
 *
 * @since 2.0
 */
public class DefaultInformationControl extends AbstractInformationControl implements DisposeListener {

	/**
	 * An information presenter determines the style presentation
	 * of information displayed in the default information control.
	 * The interface can be implemented by clients.
	 */
	public interface IInformationPresenter {

		/**
		 * Updates the given presentation of the given information and
		 * thereby may manipulate the information to be displayed. The manipulation
		 * could be the extraction of textual encoded style information etc. Returns the
		 * manipulated information.
		 * <p>
		 * <strong>Note:</strong> The given display must only be used for measuring.</p>
		 *
		 * @param display the display of the information control
		 * @param hoverInfo the information to be presented
		 * @param presentation the presentation to be updated
		 * @param maxWidth the maximal width in pixels
		 * @param maxHeight the maximal height in pixels
		 *
		 * @return the manipulated information
		 * @deprecated As of 3.2, replaced by {@link DefaultInformationControl.IInformationPresenterExtension#updatePresentation(Drawable, String, TextPresentation, int, int)}
		 */
		@Deprecated
		String updatePresentation(Display display, String hoverInfo, TextPresentation presentation, int maxWidth, int maxHeight);
	}


	/**
	 * An information presenter determines the style presentation
	 * of information displayed in the default information control.
	 * The interface can be implemented by clients.
	 *
	 * @since 3.2
	 */
	public interface IInformationPresenterExtension {

		/**
		 * Updates the given presentation of the given information and
		 * thereby may manipulate the information to be displayed. The manipulation
		 * could be the extraction of textual encoded style information etc. Returns the
		 * manipulated information.
		 * <p>
		 * Replaces {@link DefaultInformationControl.IInformationPresenter#updatePresentation(Display, String, TextPresentation, int, int)}
		 * Implementations should use the font of the given <code>drawable</code> to calculate
		 * the size of the text to be presented.
		 * </p>
		 *
		 * @param drawable the drawable of the information control
		 * @param hoverInfo the information to be presented
		 * @param presentation the presentation to be updated
		 * @param maxWidth the maximal width in pixels
		 * @param maxHeight the maximal height in pixels
		 *
		 * @return the manipulated information
		 */
		String updatePresentation(Drawable drawable, String hoverInfo, TextPresentation presentation, int maxWidth, int maxHeight);
	}


	/**
	 * Inner border thickness in pixels.
	 * @since 3.1
	 */
	private static final int INNER_BORDER= 1;

	/** The control's text widget */
	private StyledText fText;
	/** The information presenter, or <code>null</code> if none. */
	private final IInformationPresenter fPresenter;
	/** A cached text presentation */
	private final TextPresentation fPresentation= new TextPresentation();

	/**
	 * Additional styles to use for the text control.
	 * @since 3.4, previously called <code>fTextStyle</code>
	 */
	private final int fAdditionalTextStyles;

	/**
	 * Creates a default information control with the given shell as parent. An information
	 * presenter that can handle simple HTML is used to process the information to be displayed.
	 *
	 * @param parent the parent shell
	 * @param isResizeable <code>true</code> if the control should be resizable
	 * @since 3.4
	 */
	public DefaultInformationControl(Shell parent, boolean isResizeable) {
		super(parent, isResizeable);
		fAdditionalTextStyles= isResizeable ? SWT.V_SCROLL | SWT.H_SCROLL : SWT.NONE;
		fPresenter= new HTMLTextPresenter(!isResizeable);
		create();
	}

	/**
	 * Creates a default information control with the given shell as parent. An information
	 * presenter that can handle simple HTML is used to process the information to be displayed.
	 *
	 * @param parent the parent shell
	 * @param statusFieldText the text to be used in the status field or <code>null</code> to hide the status field
	 * @since 3.4
	 */
	public DefaultInformationControl(Shell parent, String statusFieldText) {
		this(parent, statusFieldText, new HTMLTextPresenter(true));
	}

	/**
	 * Creates a default information control with the given shell as parent. The
	 * given information presenter is used to process the information to be
	 * displayed.
	 *
	 * @param parent the parent shell
	 * @param statusFieldText the text to be used in the status field or <code>null</code> to hide the status field
	 * @param presenter the presenter to be used, or <code>null</code> if no presenter should be used
	 * @since 3.4
	 */
	public DefaultInformationControl(Shell parent, String statusFieldText, IInformationPresenter presenter) {
		super(parent, statusFieldText);
		fAdditionalTextStyles= SWT.NONE;
		fPresenter= presenter;
		create();
	}

	/**
	 * Creates a resizable default information control with the given shell as parent. An
	 * information presenter that can handle simple HTML is used to process the information to be
	 * displayed.
	 *
	 * @param parent the parent shell
	 * @param toolBarManager the manager or <code>null</code> if toolbar is not desired
	 * @since 3.4
	 */
	public DefaultInformationControl(Shell parent, ToolBarManager toolBarManager) {
		this(parent, toolBarManager, new HTMLTextPresenter(false));
	}

	/**
	 * Creates a resizable default information control with the given shell as
	 * parent. The given information presenter is used to process the
	 * information to be displayed.
	 *
	 * @param parent the parent shell
	 * @param toolBarManager the manager or <code>null</code> if toolbar is not desired
	 * @param presenter the presenter to be used, or <code>null</code> if no presenter should be used
	 * @since 3.4
	 */
	public DefaultInformationControl(Shell parent, ToolBarManager toolBarManager, IInformationPresenter presenter) {
		super(parent, toolBarManager);
		fAdditionalTextStyles= SWT.V_SCROLL | SWT.H_SCROLL;
		fPresenter= presenter;
		create();
	}

	/**
	 * Creates a default information control with the given shell as parent.
	 * No information presenter is used to process the information
	 * to be displayed.
	 *
	 * @param parent the parent shell
	 */
	public DefaultInformationControl(Shell parent) {
		this(parent, (String)null, null);
	}

	/**
	 * Creates a default information control with the given shell as parent. The given
	 * information presenter is used to process the information to be displayed.
	 *
	 * @param parent the parent shell
	 * @param presenter the presenter to be used
	 */
	public DefaultInformationControl(Shell parent, IInformationPresenter presenter) {
		this(parent, (String)null, presenter);
	}

	/**
	 * Creates a default information control with the given shell as parent. The
	 * given information presenter is used to process the information to be
	 * displayed. The given styles are applied to the created styled text
	 * widget.
	 *
	 * @param parent the parent shell
	 * @param shellStyle the additional styles for the shell
	 * @param style the additional styles for the styled text widget
	 * @param presenter the presenter to be used
	 * @deprecated As of 3.4, replaced by simpler constructors
	 */
	@Deprecated
	public DefaultInformationControl(Shell parent, int shellStyle, int style, IInformationPresenter presenter) {
		this(parent, shellStyle, style, presenter, null);
	}

	/**
	 * Creates a default information control with the given shell as parent. The
	 * given information presenter is used to process the information to be
	 * displayed. The given styles are applied to the created styled text
	 * widget.
	 *
	 * @param parentShell the parent shell
	 * @param shellStyle the additional styles for the shell
	 * @param style the additional styles for the styled text widget
	 * @param presenter the presenter to be used
	 * @param statusFieldText the text to be used in the status field or <code>null</code> to hide the status field
	 * @since 3.0
	 * @deprecated As of 3.4, replaced by simpler constructors
	 */
	@Deprecated
	public DefaultInformationControl(Shell parentShell, int shellStyle, final int style, IInformationPresenter presenter, String statusFieldText) {
		super(parentShell, SWT.NO_FOCUS | SWT.ON_TOP | shellStyle, statusFieldText, null);
		fAdditionalTextStyles= style;
		fPresenter= presenter;
		create();
	}

	/**
	 * Creates a default information control with the given shell as parent. The
	 * given information presenter is used to process the information to be
	 * displayed.
	 *
	 * @param parent the parent shell
	 * @param textStyles the additional styles for the styled text widget
	 * @param presenter the presenter to be used
	 * @deprecated As of 3.4, replaced by {@link #DefaultInformationControl(Shell, DefaultInformationControl.IInformationPresenter)}
	 */
	@Deprecated
	public DefaultInformationControl(Shell parent, int textStyles, IInformationPresenter presenter) {
		this(parent, textStyles, presenter, null);
	}

	/**
	 * Creates a default information control with the given shell as parent. The
	 * given information presenter is used to process the information to be
	 * displayed.
	 *
	 * @param parent the parent shell
	 * @param textStyles the additional styles for the styled text widget
	 * @param presenter the presenter to be used
	 * @param statusFieldText the text to be used in the status field or <code>null</code> to hide the status field
	 * @since 3.0
	 * @deprecated As of 3.4, replaced by {@link #DefaultInformationControl(Shell, String, DefaultInformationControl.IInformationPresenter)}
	 */
	@Deprecated
	public DefaultInformationControl(Shell parent, int textStyles, IInformationPresenter presenter, String statusFieldText) {
		super(parent, statusFieldText);
		fAdditionalTextStyles= textStyles;
		fPresenter= presenter;
		create();
	}

	@Override
	protected void createContent(Composite parent) {
		fText= new StyledText(parent, SWT.MULTI | SWT.READ_ONLY | fAdditionalTextStyles);
		fText.setForeground(parent.getForeground());
		fText.setBackground(parent.getBackground());
		fText.setFont(JFaceResources.getDialogFont());
		FillLayout layout= (FillLayout)parent.getLayout();
		if (fText.getWordWrap()) {
			// indent does not work for wrapping StyledText, see https://bugs.eclipse.org/bugs/show_bug.cgi?id=56342 and https://bugs.eclipse.org/bugs/show_bug.cgi?id=115432
			layout.marginHeight= INNER_BORDER;
			layout.marginWidth= INNER_BORDER;
		} else {
			fText.setIndent(INNER_BORDER);
		}
	}

	@Override
	public void setInformation(String content) {
		if (fPresenter == null) {
			fText.setText(content);
		} else {
			fPresentation.clear();

			int maxWidth= -1;
			int maxHeight= -1;
			Point constraints= getSizeConstraints();
			if (constraints != null) {
				maxWidth= constraints.x;
				maxHeight= constraints.y;
				if (fText.getWordWrap()) {
					maxWidth-= INNER_BORDER * 2;
					maxHeight-= INNER_BORDER * 2;
				} else {
					maxWidth-= INNER_BORDER; // indent
				}
				Rectangle trim= computeTrim();
				maxWidth-= trim.width;
				maxHeight-= trim.height;
				maxWidth-= fText.getCaret().getSize().x; // StyledText adds a border at the end of the line for the caret.
			}
			if (isResizable())
				maxHeight= Integer.MAX_VALUE;

			if (fPresenter instanceof IInformationPresenterExtension)
				content= ((IInformationPresenterExtension)fPresenter).updatePresentation(fText, content, fPresentation, maxWidth, maxHeight);
			else
				content= fPresenter.updatePresentation(getShell().getDisplay(), content, fPresentation, maxWidth, maxHeight);

			if (content != null) {
				fText.setText(content);
				TextPresentation.applyTextPresentation(fPresentation, fText);
			} else {
				fText.setText(""); //$NON-NLS-1$
			}
		}
	}

	@Override
	public void setVisible(boolean visible) {
		if (visible) {
			if (fText.getWordWrap()) {
				Point currentSize= getShell().getSize();
				getShell().pack(true);
				Point newSize= getShell().getSize();
				if (newSize.x > currentSize.x || newSize.y > currentSize.y)
					setSize(currentSize.x, currentSize.y); // restore previous size
			}
		}

		super.setVisible(visible);
	}

	@Override
	public Point computeSizeHint() {
		// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=117602
		int widthHint= SWT.DEFAULT;
		Point constraints= getSizeConstraints();
		if (constraints != null && fText.getWordWrap())
			widthHint= constraints.x;

		return getShell().computeSize(widthHint, SWT.DEFAULT, true);
	}

	@Override
	public Rectangle computeTrim() {
		return Geometry.add(super.computeTrim(), fText.computeTrim(0, 0, 0, 0));
	}

	@Override
	public void setForegroundColor(Color foreground) {
		super.setForegroundColor(foreground);
		fText.setForeground(foreground);
	}

	@Override
	public void setBackgroundColor(Color background) {
		super.setBackgroundColor(background);
		fText.setBackground(background);
	}

	@Override
	public boolean hasContents() {
		return fText.getCharCount() > 0;
	}

	/**
	 * @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
	 * @since 3.0
	 * @deprecated As of 3.2, no longer used and called
	 */
	@Deprecated
	@Override
	public void widgetDisposed(DisposeEvent event) {
	}

	@Override
	public IInformationControlCreator getInformationPresenterControlCreator() {
		return new IInformationControlCreator() {
			@Override
			public IInformationControl createInformationControl(Shell parent) {
				return new DefaultInformationControl(parent, (ToolBarManager) null, fPresenter);
			}
		};
	}

}
