org.rubypeople.rdt.internal.ui.preferences.formatter.RubyPreview.java Source code

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/*******************************************************************************
 * 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.rubypeople.rdt.internal.ui.preferences.formatter;

import java.util.Map;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceConverter;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.MarginPainter;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
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.Font;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
import org.eclipse.ui.texteditor.ChainedPreferenceStore;
import org.rubypeople.rdt.core.formatter.DefaultCodeFormatterConstants;
import org.rubypeople.rdt.internal.ui.RubyPlugin;
import org.rubypeople.rdt.internal.ui.rubyeditor.RubySourceViewer;
import org.rubypeople.rdt.internal.ui.text.IRubyPartitions;
import org.rubypeople.rdt.internal.ui.text.SimpleRubySourceViewerConfiguration;
import org.rubypeople.rdt.ui.PreferenceConstants;
import org.rubypeople.rdt.ui.text.RubyTextTools;

public abstract class RubyPreview {

    private final class RubySourcePreviewerUpdater {

        final IPropertyChangeListener fontListener = new IPropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent event) {
                if (event.getProperty().equals(PreferenceConstants.EDITOR_TEXT_FONT)) {
                    final Font font = JFaceResources.getFont(PreferenceConstants.EDITOR_TEXT_FONT);
                    fSourceViewer.getTextWidget().setFont(font);
                    if (fMarginPainter != null) {
                        fMarginPainter.initialize();
                    }
                }
            }
        };

        final IPropertyChangeListener propertyListener = new IPropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent event) {
                if (fViewerConfiguration.affectsTextPresentation(event)) {
                    fViewerConfiguration.handlePropertyChangeEvent(event);
                    fSourceViewer.invalidateTextPresentation();
                }
            }
        };

        public RubySourcePreviewerUpdater() {

            JFaceResources.getFontRegistry().addListener(fontListener);
            fPreferenceStore.addPropertyChangeListener(propertyListener);

            fSourceViewer.getTextWidget().addDisposeListener(new DisposeListener() {
                public void widgetDisposed(DisposeEvent e) {
                    JFaceResources.getFontRegistry().removeListener(fontListener);
                    fPreferenceStore.removePropertyChangeListener(propertyListener);
                }
            });
        }
    }

    protected final SimpleRubySourceViewerConfiguration fViewerConfiguration;

    protected final Document fPreviewDocument;

    protected final SourceViewer fSourceViewer;

    protected final IPreferenceStore fPreferenceStore;

    protected final MarginPainter fMarginPainter;

    protected Map fWorkingValues;

    private int fTabSize = 0;

    /**
     * Create a new Ruby preview
     * 
     * @param workingValues
     * @param parent
     */
    public RubyPreview(Map workingValues, Composite parent) {
        RubyTextTools tools = RubyPlugin.getDefault().getRubyTextTools();
        fPreviewDocument = new Document();
        fWorkingValues = workingValues;
        tools.setupRubyDocumentPartitioner(fPreviewDocument, IRubyPartitions.RUBY_PARTITIONING);

        IPreferenceStore[] chain = { RubyPlugin.getDefault().getCombinedPreferenceStore() };
        fPreferenceStore = new ChainedPreferenceStore(chain);
        fSourceViewer = new RubySourceViewer(parent, null, null, false,
                SWT.READ_ONLY | SWT.V_SCROLL | SWT.H_SCROLL | SWT.BORDER, fPreferenceStore);
        fViewerConfiguration = new SimpleRubySourceViewerConfiguration(tools.getColorManager(), fPreferenceStore,
                null, IRubyPartitions.RUBY_PARTITIONING, true);
        fSourceViewer.configure(fViewerConfiguration);
        fSourceViewer.getTextWidget().setFont(JFaceResources.getFont(PreferenceConstants.EDITOR_TEXT_FONT));

        fMarginPainter = new MarginPainter(fSourceViewer);
        final RGB rgb = PreferenceConverter.getColor(fPreferenceStore,
                AbstractDecoratedTextEditorPreferenceConstants.EDITOR_PRINT_MARGIN_COLOR);
        fMarginPainter.setMarginRulerColor(tools.getColorManager().getColor(rgb));
        fSourceViewer.addPainter(fMarginPainter);

        new RubySourcePreviewerUpdater();
        fSourceViewer.setDocument(fPreviewDocument);
    }

    public Control getControl() {
        return fSourceViewer.getControl();
    }

    public StyledText getTextWidget() {
        return fSourceViewer.getTextWidget();
    }

    public void update() {
        if (fWorkingValues == null) {
            fPreviewDocument.set(""); //$NON-NLS-1$
            return;
        }

        // update the print margin
        final String value = (String) fWorkingValues.get(DefaultCodeFormatterConstants.FORMATTER_LINE_SPLIT);
        final int lineWidth = getPositiveIntValue(value, 0);
        fMarginPainter.setMarginRulerColumn(lineWidth);

        // update the tab size
        final int tabSize = getPositiveIntValue(
                (String) fWorkingValues.get(DefaultCodeFormatterConstants.FORMATTER_TAB_SIZE), 0);
        if (tabSize != fTabSize)
            fSourceViewer.getTextWidget().setTabs(tabSize);
        fTabSize = tabSize;

        final StyledText widget = (StyledText) fSourceViewer.getControl();
        final int height = widget.getClientArea().height;
        final int top0 = widget.getTopPixel();

        final int totalPixels0 = getHeightOfAllLines(widget);
        final int topPixelRange0 = totalPixels0 > height ? totalPixels0 - height : 0;

        widget.setRedraw(false);
        doFormatPreview();
        fSourceViewer.setSelection(null);

        final int totalPixels1 = getHeightOfAllLines(widget);
        final int topPixelRange1 = totalPixels1 > height ? totalPixels1 - height : 0;

        final int top1 = topPixelRange0 > 0 ? (int) (topPixelRange1 * top0 / (double) topPixelRange0) : 0;
        widget.setTopPixel(top1);
        widget.setRedraw(true);
    }

    private int getHeightOfAllLines(StyledText styledText) {
        int height = 0;
        int lineCount = styledText.getLineCount();
        for (int i = 0; i < lineCount; i++) {
            // TODO Uncomment the line below and delete on after when moving to
            // Eclipse 3.2
            // ECLIPSE 3.2
            // height= height +
            // styledText.getLineHeight(styledText.getOffsetAtLine(i));
            height = height + styledText.getLineHeight();
        }
        return height;
    }

    protected abstract void doFormatPreview();

    private static int getPositiveIntValue(String string, int defaultValue) {
        try {
            int i = Integer.parseInt(string);
            if (i >= 0) {
                return i;
            }
        } catch (NumberFormatException e) {
        }
        return defaultValue;
    }

    public final Map getWorkingValues() {
        return fWorkingValues;
    }

    public final void setWorkingValues(Map workingValues) {
        fWorkingValues = workingValues;
    }
}