com.patrick_vane.unrealscript.editor.default_classes.HoverInformationControl.java Source code

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/*******************************************************************************
 * Copyright (c) 2000, 2012 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 com.patrick_vane.unrealscript.editor.default_classes;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jdt.ui.PreferenceConstants;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IInformationControl;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.IInformationControlExtension;
import org.eclipse.jface.text.IInformationControlExtension3;
import org.eclipse.jface.text.IInformationControlExtension5;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.SourceViewer;
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.events.FocusListener;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import com.patrick_vane.unrealscript.editor.UnrealScriptEditor;
import com.patrick_vane.unrealscript.editor.constants.TextAttributeConstant;
import com.patrick_vane.unrealscript.editor.syntaxcolor.UnrealScriptSyntaxColor;

/**
 * Source viewer based implementation of <code>IInformationControl</code>.
 * Displays information in a source viewer.
 * 
 * @since 3.0
 */
@SuppressWarnings("unused")
public class HoverInformationControl implements IInformationControl, IInformationControlExtension,
        IInformationControlExtension3, IInformationControlExtension5, DisposeListener {
    private IInformationControlCreator creator;

    /** The control's shell */
    private Shell fShell;
    /** The control's text widget */
    private StyledText fText;
    /** The text font (do not dispose!) */
    private Font fTextFont;
    /** The control's source viewer */
    private SourceViewer fViewer;
    /**
     * The optional status field.
     * 
     * @since 3.0
     */
    private Label fStatusField;
    /**
     * The separator for the optional status field.
     * 
     * @since 3.0
     */
    private Label fSeparator;
    /**
     * The font of the optional status text label.
     * 
     * @since 3.0
     */
    private Font fStatusTextFont;
    /**
     * The color of the optional status text label or <code>null</code> if none.
     * 
     * @since 3.6
     */
    private Color fStatusTextForegroundColor;
    /**
     * The width size constraint.
     * 
     * @since 3.2
     */
    private int fMaxWidth = SWT.DEFAULT;
    /**
     * The height size constraint.
     * 
     * @since 3.2
     */
    private int fMaxHeight = SWT.DEFAULT;
    /**
     * The orientation of the shell
     * 
     * @since 3.4
     */
    private final int fOrientation;

    private Color fBackgroundColor;
    private boolean fIsSystemBackgroundColor = true;

    /**
     * Creates a source viewer information control with the given shell as parent. The given
     * styles are applied to the created styled text widget. The status field will
     * contain the given text or be hidden.
     * 
     * @param parent
     *            the parent shell
     * @param isResizable
     *            <code>true</code> if resizable
     * @param orientation
     *            the orientation
     * @param statusFieldText
     *            the text to be used in the optional status field
     *            or <code>null</code> if the status field should be hidden
     */
    public HoverInformationControl(IInformationControlCreator creator, Shell parent, boolean isResizable,
            int orientation, String statusFieldText) {
        this.creator = creator;

        Assert.isLegal(
                orientation == SWT.RIGHT_TO_LEFT || orientation == SWT.LEFT_TO_RIGHT || orientation == SWT.NONE);
        fOrientation = orientation;

        GridLayout layout;
        GridData gd;

        int shellStyle = SWT.TOOL | SWT.ON_TOP | orientation | (isResizable ? SWT.RESIZE : 0);
        int textStyle = SWT.SHELL_TRIM | (isResizable ? SWT.V_SCROLL | SWT.H_SCROLL : 0);

        fShell = new Shell(parent, SWT.NO_FOCUS | SWT.ON_TOP | shellStyle);
        Display display = fShell.getDisplay();

        initializeColors();

        Composite composite = fShell;
        layout = new GridLayout(1, false);
        layout.marginHeight = 0;
        layout.marginWidth = 0;
        composite.setLayout(layout);
        gd = new GridData(GridData.FILL_HORIZONTAL);
        composite.setLayoutData(gd);

        if (statusFieldText != null) {
            composite = new Composite(composite, SWT.NONE);
            layout = new GridLayout(1, false);
            layout.marginHeight = 0;
            layout.marginWidth = 0;
            layout.verticalSpacing = 1;
            composite.setLayout(layout);
            gd = new GridData(GridData.FILL_BOTH);
            composite.setLayoutData(gd);
            composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
            composite.setBackground(fBackgroundColor);
        }

        // Source viewer
        fViewer = new SourceViewer(composite, null, null, false, textStyle);
        UnrealScriptEditor editor = new UnrealScriptEditor();
        fViewer.configure(editor.getConfiguration());
        fViewer.setEditable(false);

        fText = fViewer.getTextWidget();
        gd = new GridData(GridData.BEGINNING | GridData.FILL_BOTH);
        fText.setLayoutData(gd);
        fText.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
        fText.setBackground(fBackgroundColor);

        initializeFont();

        fText.addKeyListener(new KeyListener() {

            @Override
            public void keyPressed(KeyEvent e) {
                if (e.character == 0x1B) // ESC
                    fShell.dispose();
            }

            @Override
            public void keyReleased(KeyEvent e) {
            }
        });

        // Status field
        if (statusFieldText != null) {

            // Horizontal separator line
            fSeparator = new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL | SWT.LINE_DOT);
            fSeparator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

            // Status field label
            fStatusField = new Label(composite, SWT.RIGHT);
            fStatusField.setText(statusFieldText);
            Font font = fStatusField.getFont();
            FontData[] fontDatas = font.getFontData();
            for (int i = 0; i < fontDatas.length; i++)
                fontDatas[i].setHeight(fontDatas[i].getHeight() * 9 / 10);
            fStatusTextFont = new Font(fStatusField.getDisplay(), fontDatas);
            fStatusField.setFont(fStatusTextFont);
            GridData gd2 = new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_BEGINNING);
            fStatusField.setLayoutData(gd2);

            RGB defaultColor = TextAttributeConstant.createDefault().getForeground().getRGB();
            fStatusTextForegroundColor = new Color(fStatusField.getDisplay(),
                    blend(fBackgroundColor.getRGB(), defaultColor, 0.56f));
            fStatusField.setForeground(fStatusTextForegroundColor);
            fStatusField.setBackground(fBackgroundColor);
        }

        addDisposeListener(this);
    }

    /**
     * Returns an RGB that lies between the given foreground and background
     * colors using the given mixing factor. A <code>factor</code> of 1.0 will produce a
     * color equal to <code>fg</code>, while a <code>factor</code> of 0.0 will produce one
     * equal to <code>bg</code>.
     * 
     * @param bg
     *            the background color
     * @param fg
     *            the foreground color
     * @param factor
     *            the mixing factor, must be in [0,&nbsp;1]
     * 
     * @return the interpolated color
     * @since 3.6
     */
    private static RGB blend(RGB bg, RGB fg, float factor) {
        // copy of org.eclipse.jface.internal.text.revisions.Colors#blend(..)
        Assert.isLegal(bg != null);
        Assert.isLegal(fg != null);
        Assert.isLegal(factor >= 0f && factor <= 1f);

        float complement = 1f - factor;
        return new RGB((int) (complement * bg.red + factor * fg.red),
                (int) (complement * bg.green + factor * fg.green), (int) (complement * bg.blue + factor * fg.blue));
    }

    private void initializeColors() {
        RGB bgRGB = getVisibleBackgroundColor(fShell.getDisplay());
        if (bgRGB != null) {
            fBackgroundColor = new Color(fShell.getDisplay(), bgRGB);
            fIsSystemBackgroundColor = false;
        } else {
            fBackgroundColor = fShell.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND);
            fIsSystemBackgroundColor = true;
        }
    }

    /**
     * Returns <code>null</code> if {@link SWT#COLOR_INFO_BACKGROUND} is visibly distinct from the
     * default source text color. Otherwise, returns the editor background color.
     * 
     * @param display
     *            the display
     * @return an RGB or <code>null</code>
     * @since 3.6.1
     */
    public static RGB getVisibleBackgroundColor(Display display) {
        float[] infoBgHSB = display.getSystemColor(SWT.COLOR_INFO_BACKGROUND).getRGB().getHSB();

        Color defaultColor = TextAttributeConstant.createDefault().getForeground();
        RGB defaultRGB = defaultColor != null ? defaultColor.getRGB() : new RGB(255, 255, 255);
        float[] defaultHSB = defaultRGB.getHSB();

        if (Math.abs(infoBgHSB[2] - defaultHSB[2]) < 0.5f) {
            return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND).getRGB();
        }
        return null;
    }

    /**
     * Initialize the font to the editor font.
     * 
     * @since 3.2
     */
    private void initializeFont() {
        fTextFont = JFaceResources.getFont(PreferenceConstants.EDITOR_TEXT_FONT);
        StyledText styledText = getViewer().getTextWidget();
        styledText.setFont(fTextFont);
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension2#setInput(java.lang.Object)
     */
    public void setInput(Object input) {
        if (input instanceof String)
            setInformation((String) input);
        else
            setInformation(null);
    }

    /*
     * @see IInformationControl#setInformation(String)
     */
    @Override
    public void setInformation(String content) {
        if (content == null) {
            fViewer.setInput(null);
            return;
        }

        IDocument doc = new Document(content);
        UnrealScriptSyntaxColor.setupDocumentPartitioner(doc);
        fViewer.setInput(doc);
    }

    /*
     * @see IInformationControl#setVisible(boolean)
     */
    @Override
    public void setVisible(boolean visible) {
        fShell.setVisible(visible);
    }

    /**
     * {@inheritDoc}
     * 
     * @since 3.0
     */
    @Override
    public void widgetDisposed(DisposeEvent event) {
        if (fStatusTextFont != null && !fStatusTextFont.isDisposed())
            fStatusTextFont.dispose();
        fStatusTextFont = null;

        if (fStatusTextForegroundColor != null && !fStatusTextForegroundColor.isDisposed())
            fStatusTextForegroundColor.dispose();
        fStatusTextForegroundColor = null;

        fTextFont = null;
        fShell = null;
        fText = null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final void dispose() {
        if (!fIsSystemBackgroundColor)
            fBackgroundColor.dispose();
        if (fShell != null && !fShell.isDisposed())
            fShell.dispose();
        else
            widgetDisposed(null);
    }

    /*
     * @see IInformationControl#setSize(int, int)
     */
    @Override
    public void setSize(int width, int height) {
        fShell.setSize(width, height);
    }

    /*
     * @see IInformationControl#setLocation(Point)
     */
    @Override
    public void setLocation(Point location) {
        fShell.setLocation(location);
    }

    /*
     * @see IInformationControl#setSizeConstraints(int, int)
     */
    @Override
    public void setSizeConstraints(int maxWidth, int maxHeight) {
        fMaxWidth = maxWidth;
        fMaxHeight = maxHeight;
    }

    /*
     * @see IInformationControl#computeSizeHint()
     */
    @Override
    public Point computeSizeHint() {
        // compute the preferred size
        int x = SWT.DEFAULT;
        int y = SWT.DEFAULT;
        Point size = fShell.computeSize(x, y);
        if (size.x > fMaxWidth)
            x = fMaxWidth;
        if (size.y > fMaxHeight)
            y = fMaxHeight;

        // recompute using the constraints if the preferred size is larger than the constraints
        if (x != SWT.DEFAULT || y != SWT.DEFAULT)
            size = fShell.computeSize(x, y, false);

        return size;
    }

    /*
     * @see IInformationControl#addDisposeListener(DisposeListener)
     */
    @Override
    public void addDisposeListener(DisposeListener listener) {
        fShell.addDisposeListener(listener);
    }

    /*
     * @see IInformationControl#removeDisposeListener(DisposeListener)
     */
    @Override
    public void removeDisposeListener(DisposeListener listener) {
        fShell.removeDisposeListener(listener);
    }

    /*
     * @see IInformationControl#setForegroundColor(Color)
     */
    @Override
    public void setForegroundColor(Color foreground) {
        fText.setForeground(foreground);
    }

    /*
     * @see IInformationControl#setBackgroundColor(Color)
     */
    @Override
    public void setBackgroundColor(Color background) {
        fText.setBackground(background);
    }

    /*
     * @see IInformationControl#isFocusControl()
     */
    @Override
    public boolean isFocusControl() {
        return fShell.getDisplay().getActiveShell() == fShell;
    }

    /*
     * @see IInformationControl#setFocus()
     */
    @Override
    public void setFocus() {
        fShell.forceFocus();
        fText.setFocus();
    }

    /*
     * @see IInformationControl#addFocusListener(FocusListener)
     */
    @Override
    public void addFocusListener(FocusListener listener) {
        fText.addFocusListener(listener);
    }

    /*
     * @see IInformationControl#removeFocusListener(FocusListener)
     */
    @Override
    public void removeFocusListener(FocusListener listener) {
        fText.removeFocusListener(listener);
    }

    /*
     * @see IInformationControlExtension#hasContents()
     */
    @Override
    public boolean hasContents() {
        return fText.getCharCount() > 0;
    }

    protected ISourceViewer getViewer() {
        return fViewer;
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim()
     * @since 3.4
     */
    @Override
    public Rectangle computeTrim() {
        Rectangle trim = fShell.computeTrim(0, 0, 0, 0);
        addInternalTrim(trim);
        return trim;
    }

    /**
     * Adds the internal trimmings to the given trim of the shell.
     * 
     * @param trim
     *            the shell's trim, will be updated
     * @since 3.4
     */
    private void addInternalTrim(Rectangle trim) {
        Rectangle textTrim = fText.computeTrim(0, 0, 0, 0);
        trim.x += textTrim.x;
        trim.y += textTrim.y;
        trim.width += textTrim.width;
        trim.height += textTrim.height;

        if (fStatusField != null) {
            trim.height += fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
            trim.height += fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
            trim.height += 1; // verticalSpacing
        }
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension3#getBounds()
     * @since 3.4
     */
    @Override
    public Rectangle getBounds() {
        return fShell.getBounds();
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension3#restoresLocation()
     * @since 3.4
     */
    @Override
    public boolean restoresLocation() {
        return false;
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension3#restoresSize()
     * @since 3.4
     */
    @Override
    public boolean restoresSize() {
        return false;
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension5#getInformationPresenterControlCreator()
     * @since 3.4
     */
    @Override
    public IInformationControlCreator getInformationPresenterControlCreator() {
        return new IInformationControlCreator() {
            @Override
            public IInformationControl createInformationControl(Shell parent) {
                return new HoverInformationControl(this, parent, true, SWT.LEFT_TO_RIGHT, null);
            }
        };
        //return creator;
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension5#containsControl(org.eclipse.swt.widgets.Control)
     * @since 3.4
     */
    @Override
    public boolean containsControl(Control control) {
        do {
            if (control == fShell)
                return true;
            if (control instanceof Shell)
                return false;
            control = control.getParent();
        } while (control != null);
        return false;
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension5#isVisible()
     * @since 3.4
     */
    @Override
    public boolean isVisible() {
        return fShell != null && !fShell.isDisposed() && fShell.isVisible();
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension5#computeSizeConstraints(int, int)
     */
    @Override
    public Point computeSizeConstraints(int widthInChars, int heightInChars) {
        GC gc = new GC(fText);
        gc.setFont(fTextFont);
        int width = gc.getFontMetrics().getAverageCharWidth();
        int height = gc.getFontMetrics().getHeight();
        gc.dispose();

        return new Point(widthInChars * width, heightInChars * height);
    }
}