org.eclipse.xtext.xbase.ui.hover.XbaseInformationControl.java Source code

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/*******************************************************************************
 * Copyright (c) 2012 itemis AG (http://www.itemis.eu) 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
 *******************************************************************************/
package org.eclipse.xtext.xbase.ui.hover;

import java.io.IOException;
import java.io.StringReader;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.internal.text.html.HTML2TextReader;
import org.eclipse.jface.internal.text.html.HTMLPrinter;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.AbstractInformationControl;
import org.eclipse.jface.text.IDelayedInputChangeProvider;
import org.eclipse.jface.text.IInformationControlExtension2;
import org.eclipse.jface.text.IInputChangedListener;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.browser.Browser;
import org.eclipse.swt.browser.LocationListener;
import org.eclipse.swt.browser.OpenWindowListener;
import org.eclipse.swt.browser.ProgressAdapter;
import org.eclipse.swt.browser.ProgressEvent;
import org.eclipse.swt.browser.WindowEvent;
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.TextLayout;
import org.eclipse.swt.graphics.TextStyle;
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.Layout;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Slider;
import org.eclipse.xtext.resource.XtextResource;
import org.eclipse.xtext.resource.XtextResourceSet;
import org.eclipse.xtext.ui.editor.embedded.EmbeddedEditor;
import org.eclipse.xtext.ui.editor.embedded.EmbeddedEditorModelAccess;
import org.eclipse.xtext.ui.editor.embedded.IEditedResourceProvider;
import org.eclipse.xtext.ui.editor.hover.html.IXtextBrowserInformationControl;
import org.eclipse.xtext.ui.editor.hover.html.XtextBrowserInformationControlInput;
import org.eclipse.xtext.ui.editor.validation.IValidationIssueProcessor;
import org.eclipse.xtext.validation.Issue;

/**
 * @author Holger Schill - Initial contribution and API most of the code is copied from
 *{@link org.eclipse.jface.internal.text.html.BrowserInformationControl} due to visibility problems. The methods and
 *                                                                      fields that are modified are marked
 * @since 2.3
 */
@SuppressWarnings("restriction")
public class XbaseInformationControl extends AbstractInformationControl
        implements IInformationControlExtension2, IDelayedInputChangeProvider, IXtextBrowserInformationControl {

    /**
     * Xbase Modifications
     */
    private XtextBrowserInformationControlInput fInput;
    private Composite detailPaneComposite;
    private XbaseHoverConfiguration xbaseHoverConfiguration;
    private EmbeddedEditorModelAccess embeddedEditorAccess;
    private HoverEditedResourceProvider resourceProvider;
    private EmbeddedEditor embeddedEditor;
    private SashForm fSashForm;

    /**
     * Xbase - modification Added XbaseHoverConfiguration because we do not have DI here
     */
    public XbaseInformationControl(Shell parent, String symbolicFontName, String statusFieldText,
            XbaseHoverConfiguration xbaseHoverConfiguration) {
        super(parent, statusFieldText);
        fSymbolicFontName = symbolicFontName;
        this.xbaseHoverConfiguration = xbaseHoverConfiguration;
        create();
    }

    /**
     * Xbase - modification Added XbaseHoverConfiguration because we do not have DI here
     */
    public XbaseInformationControl(Shell parent, String symbolicFontName, ToolBarManager toolBarManager,
            XbaseHoverConfiguration xbaseHoverConfiguration) {
        super(parent, toolBarManager);
        fSymbolicFontName = symbolicFontName;
        this.xbaseHoverConfiguration = xbaseHoverConfiguration;
        create();
    }

    /**
     * Xbase - modification+ added detailPane
     */
    @Override
    protected void createContent(Composite parent) {
        fSashForm = new SashForm(parent, parent.getStyle());
        fSashForm.setOrientation(SWT.VERTICAL);
        fBrowser = new Browser(fSashForm, SWT.NONE);
        fBrowser.setJavascriptEnabled(false);
        Display display = getShell().getDisplay();
        fBrowser.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
        fBrowser.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
        fBrowser.addProgressListener(new ProgressAdapter() {
            @Override
            public void completed(ProgressEvent event) {
                fCompleted = true;
            }
        });
        fBrowser.addOpenWindowListener(new OpenWindowListener() {
            @Override
            public void open(WindowEvent event) {
                event.required = true; // Cancel opening of new windows
            }
        });
        // Replace browser's built-in context menu with none
        fSashForm.setMenu(new Menu(getShell(), SWT.NONE));
        detailPaneComposite = createComposite(fSashForm, 1, 1, GridData.FILL_BOTH);
        Layout layout = detailPaneComposite.getLayout();
        if (layout instanceof GridLayout) {
            GridLayout gl = (GridLayout) layout;
            gl.marginHeight = 0;
            gl.marginWidth = 0;
            gl.numColumns = 1;
        }
        detailPaneComposite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
        detailPaneComposite.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
        resourceProvider = new HoverEditedResourceProvider();
        embeddedEditor = xbaseHoverConfiguration.getEditorFactory().newEditor(resourceProvider).readOnly()
                .processIssuesBy(new IValidationIssueProcessor() {
                    @Override
                    public void processIssues(List<Issue> issues, IProgressMonitor monitor) {
                    }
                }).withParent(detailPaneComposite);
        Control viewerControl = embeddedEditor.getViewer().getControl();
        viewerControl.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
        viewerControl.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
        embeddedEditor.getDocument().setValidationJob(null);
        createTextLayout();
    }

    protected Composite createComposite(Composite parent, int columns, int hspan, int fill) {
        Composite g = new Composite(parent, SWT.NONE);
        g.setLayout(new GridLayout(columns, false));
        g.setFont(parent.getFont());
        GridData gd = new GridData(fill);
        gd.horizontalSpan = hspan;
        gd.grabExcessHorizontalSpace = true;
        g.setLayoutData(gd);
        return g;
    }

    /**
     * Creates the synthetic resource for the embedded editor Allows to set the ClasspathContext afterwards
     */
    public class HoverEditedResourceProvider implements IEditedResourceProvider {
        private XtextResourceSet xtextResourceSet;

        @Override
        public XtextResource createResource() {
            final String SYNTHETIC_SCHEME = "synthetic";
            xtextResourceSet = xbaseHoverConfiguration.createResourceSet();
            if (fInput != null) {
                XtextResourceSet resourceSet = (XtextResourceSet) fInput.getElement().eResource().getResourceSet();
                xtextResourceSet.setClasspathURIContext(resourceSet.getClasspathURIContext());
            }
            URI uri = URI.createURI(
                    SYNTHETIC_SCHEME + ":/unsugaredExpression." + xbaseHoverConfiguration.getFileExtension());
            XtextResource resource = (XtextResource) xtextResourceSet.createResource(uri);
            xtextResourceSet.getResources().add(resource);
            return resource;

        }

        public void setContext(Object object) {
            xtextResourceSet.setClasspathURIContext(object);
        }
    }

    /**
     * Xbase - modification added detailPane
     */
    @Override
    public void setInput(Object input) {
        Assert.isLegal(
                input == null || input instanceof String || input instanceof XtextBrowserInformationControlInput,
                String.valueOf(input));

        if (input instanceof String) {
            setInformation((String) input);
            return;
        }
        if (input instanceof XtextBrowserInformationControlInput)
            fInput = (XtextBrowserInformationControlInput) input;

        String content = null;
        if (fInput != null)
            content = fInput.getHtml();

        fBrowserHasContent = content != null && content.length() > 0;

        if (!fBrowserHasContent)
            content = "<html><body ></html>"; //$NON-NLS-1$

        boolean RTL = (getShell().getStyle() & SWT.RIGHT_TO_LEFT) != 0;
        boolean resizable = isResizable();

        // The default "overflow:auto" would not result in a predictable width for the client area
        // and the re-wrapping would cause visual noise
        String[] styles = null;
        if (RTL && resizable)
            styles = new String[] { "direction:rtl;", "overflow:scroll;", "word-wrap:break-word;" }; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
        else if (RTL && !resizable)
            styles = new String[] { "direction:rtl;", "overflow:hidden;", "word-wrap:break-word;" }; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
        else if (!resizable)
            //XXX: In IE, "word-wrap: break-word;" causes bogus wrapping even in non-broken words :-(see e.g. Javadoc of String).
            // Re-check whether we really still need this now that the Javadoc Hover header already sets this style.
            styles = new String[] { "overflow:hidden;"/*, "word-wrap: break-word;"*/ }; //$NON-NLS-1$
        else
            styles = new String[] { "overflow:scroll;" }; //$NON-NLS-1$

        StringBuffer buffer = new StringBuffer(content);
        HTMLPrinter.insertStyles(buffer, styles);
        content = buffer.toString();

        /*
         * XXX: Should add some JavaScript here that shows something like
         * "(continued...)" or "..." at the end of the visible area when the page overflowed
         * with "overflow:hidden;".
         */

        fCompleted = false;
        fBrowser.setText(content);
        String unsugaredExpression = "";
        if (fInput != null && fInput instanceof XbaseInformationControlInput) {
            XbaseInformationControlInput castedInput = (XbaseInformationControlInput) fInput;
            unsugaredExpression = castedInput.getUnsugaredExpression();
            if (unsugaredExpression != null && unsugaredExpression.length() > 0) {
                EObject element = fInput.getElement();
                if (element != null && element.eResource() != null
                        && element.eResource().getResourceSet() != null) {
                    // FIXME: No arguments need when https://bugs.eclipse.org/bugs/show_bug.cgi?id=368827 is solved
                    // THEN move to createContent as it was before
                    if (embeddedEditorAccess == null)
                        embeddedEditorAccess = embeddedEditor.createPartialEditor("", "INITIAL CONTENT", "", false);
                    resourceProvider.setContext(
                            ((XtextResourceSet) element.eResource().getResourceSet()).getClasspathURIContext());
                } else
                    return;
                embeddedEditorAccess.updateModel(castedInput.getPrefix(), unsugaredExpression,
                        castedInput.getSuffix());
            }
        }

        if (unsugaredExpression != null && unsugaredExpression.length() > 0)
            fSashForm.setWeights(new int[] { 7, 3 });
        else
            fSashForm.setWeights(new int[] { 10, 0 });
        Object[] listeners = fInputChangeListeners.getListeners();
        for (int i = 0; i < listeners.length; i++)
            ((IInputChangedListener) listeners[i]).inputChanged(fInput);

    }

    /**
     * Xbase - modification added some space for the detailPane
     */
    @Override
    public Point computeSizeHint() {
        Point sizeConstraints = getSizeConstraints();
        Rectangle trim = computeTrim();
        int height = trim.height;

        //FIXME: The HTML2TextReader does not render <p> like a browser.
        // Instead of inserting an empty line, it just adds a single line break.
        // Furthermore, the indentation of <dl><dd> elements is too small (e.g with a long @see line)
        TextPresentation presentation = new TextPresentation();
        HTML2TextReader reader = new HTML2TextReader(new StringReader(fInput.getHtml()), presentation);
        String text;
        try {
            text = reader.getString();
        } catch (IOException e) {
            text = ""; //$NON-NLS-1$
        }

        Rectangle bounds = computeBounds(sizeConstraints, trim, presentation, text);

        int minWidth = bounds.width;
        height = height + bounds.height;

        if (fInput instanceof XbaseInformationControlInput) {
            String unsugaredExpression = ((XbaseInformationControlInput) fInput).getUnsugaredExpression();
            if (unsugaredExpression != null && unsugaredExpression.length() > 0) {
                Rectangle detailBounds = computeBounds(sizeConstraints, trim, null, unsugaredExpression);
                minWidth = Math.max(minWidth, detailBounds.width);
                height += detailBounds.height + 30;
            }
        }

        // Add some air to accommodate for different browser renderings
        height += 15;
        minWidth += 70;

        // Apply max size constraints
        if (sizeConstraints != null) {
            if (sizeConstraints.x != SWT.DEFAULT)
                minWidth = Math.min(sizeConstraints.x, minWidth + trim.width);
            if (sizeConstraints.y != SWT.DEFAULT)
                height = Math.min(sizeConstraints.y, height);
        }

        // Ensure minimal size
        int width = Math.max(MIN_WIDTH, minWidth);
        height = Math.max(MIN_HEIGHT, height);
        return new Point(width, height);
    }

    /**
     * Xbase - modification
     * Reuse of bounds calculation
     */
    private Rectangle computeBounds(Point sizeConstraints, Rectangle trim, TextPresentation presentation,
            String text) {
        fTextLayout.setText(text);
        fTextLayout.setWidth(sizeConstraints == null ? SWT.DEFAULT : sizeConstraints.x - trim.width);
        if (presentation != null) {
            @SuppressWarnings("rawtypes")
            Iterator iter = presentation.getAllStyleRangeIterator();
            while (iter.hasNext()) {
                StyleRange sr = (StyleRange) iter.next();
                if (sr.fontStyle == SWT.BOLD)
                    fTextLayout.setStyle(fBoldStyle, sr.start, sr.start + sr.length - 1);
            }
        }
        Rectangle bounds = fTextLayout.getBounds(); // does not return minimum width, see https://bugs.eclipse.org/bugs/show_bug.cgi?id=217446
        int lineCount = fTextLayout.getLineCount();
        int textWidth = 0;
        for (int i = 0; i < lineCount; i++) {
            Rectangle rect = fTextLayout.getLineBounds(i);
            int lineWidth = rect.x + rect.width;
            if (i == 0)
                lineWidth += fInput.getLeadingImageWidth();
            textWidth = Math.max(textWidth, lineWidth);
        }
        bounds.width = textWidth;
        fTextLayout.setText(""); //$NON-NLS-1$
        return bounds;
    }

    /**
     * Xbase - modification
     */
    @Override
    public XtextBrowserInformationControlInput getInput() {
        return fInput;
    }

    /**
     * Xbase - modification
     */
    @Override
    public Point computeSizeConstraints(int widthInChars, int heightInChars) {
        if (fSymbolicFontName == null)
            return null;

        GC gc = new GC(fBrowser);
        Font font = JFaceResources.getFont(fSymbolicFontName);
        gc.setFont(font);
        int width = gc.getFontMetrics().getAverageCharWidth();
        int height = gc.getFontMetrics().getHeight();
        gc.dispose();

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

    //------------------ Original implementation
    /**
     * Tells whether the SWT Browser widget and hence this information control is available.
     * 
     * @param parent
     *            the parent component used for checking or <code>null</code> if none
     * @return <code>true</code> if this control is available
     */
    public static boolean isAvailable(Composite parent) {
        if (!fgAvailabilityChecked) {
            try {
                Browser browser = new Browser(parent, SWT.NONE);
                browser.dispose();

                fgIsAvailable = true;

                Slider sliderV = new Slider(parent, SWT.VERTICAL);
                Slider sliderH = new Slider(parent, SWT.HORIZONTAL);
                int width = sliderV.computeSize(SWT.DEFAULT, SWT.DEFAULT).x;
                int height = sliderH.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
                fgScrollBarSize = new Point(width, height);
                sliderV.dispose();
                sliderH.dispose();
            } catch (SWTError er) {
                fgIsAvailable = false;
            } finally {
                fgAvailabilityChecked = true;
            }
        }

        return fgIsAvailable;
    }

    /**
     * Minimal size constraints.
     * 
     * @since 3.2
     */
    private static final int MIN_WIDTH = 80;

    private static final int MIN_HEIGHT = 50;

    /**
     * Availability checking cache.
     */
    private static boolean fgIsAvailable = false;

    private static boolean fgAvailabilityChecked = false;

    /**
     * Cached scroll bar width and height
     * 
     * @since 3.4
     */
    private static Point fgScrollBarSize;

    /** The control's browser widget */
    private Browser fBrowser;

    /** Tells whether the browser has content */
    private boolean fBrowserHasContent;

    /** Text layout used to approximate size of content when rendered in browser */
    private TextLayout fTextLayout;

    /** Bold text style */
    private TextStyle fBoldStyle;

    /**
     * <code>true</code> if the browser has completed loading of the last input set via {@link #setInformation(String)}
     * .
     * 
     * @since 3.4
     */
    private boolean fCompleted = false;

    /**
     * The listener to be notified when a delayed location changing event happened.
     * 
     * @since 3.4
     */
    private IInputChangedListener fDelayedInputChangeListener;

    /**
     * The listeners to be notified when the input changed.
     * 
     * @since 3.4
     */
    private ListenerList/*<IInputChangedListener>*/ fInputChangeListeners = new ListenerList(ListenerList.IDENTITY);

    /**
     * The symbolic name of the font used for size computations, or <code>null</code> to use dialog font.
     * 
     * @since 3.4
     */
    private final String fSymbolicFontName;

    /*
     * @see IInformationControl#setVisible(boolean)
     */
    @Override
    public void setVisible(boolean visible) {
        Shell shell = getShell();
        if (shell.isVisible() == visible)
            return;

        if (!visible) {
            super.setVisible(false);
            setInput(null);
            return;
        }

        /*
         * The Browser widget flickers when made visible while it is not completely loaded.
         * The fix is to delay the call to setVisible until either loading is completed
         * (see ProgressListener in constructor), or a timeout has been reached.
         */
        final Display display = shell.getDisplay();

        // Make sure the display wakes from sleep after timeout:
        display.timerExec(100, new Runnable() {
            @Override
            public void run() {
                fCompleted = true;
            }
        });

        while (!fCompleted) {
            // Drive the event loop to process the events required to load the browser widget's contents:
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }

        shell = getShell();
        if (shell == null || shell.isDisposed())
            return;

        /*
         * Avoids flickering when replacing hovers, especially on Vista in ON_CLICK mode.
         * Causes flickering on GTK. Carbon does not care.
         */
        if ("win32".equals(SWT.getPlatform())) //$NON-NLS-1$
            shell.moveAbove(null);

        super.setVisible(true);
    }

    /*
     * @see org.eclipse.jface.text.AbstractInformationControl#setSize(int, int)
     */
    @Override
    public void setSize(int width, int height) {
        fSashForm.setRedraw(false); // avoid flickering
        try {
            super.setSize(width, height);
        } finally {
            fSashForm.setRedraw(true);
        }
    }

    /**
     * Creates and initializes the text layout used to compute the size hint.
     * 
     * @since 3.2
     */
    private void createTextLayout() {
        fTextLayout = new TextLayout(fSashForm.getDisplay());

        // Initialize fonts
        String symbolicFontName = fSymbolicFontName == null ? JFaceResources.DIALOG_FONT : fSymbolicFontName;
        Font font = JFaceResources.getFont(symbolicFontName);
        fTextLayout.setFont(font);
        fTextLayout.setWidth(-1);
        font = JFaceResources.getFontRegistry().getBold(symbolicFontName);
        fBoldStyle = new TextStyle(font, null, null);

        // Compute and set tab width
        fTextLayout.setText("    "); //$NON-NLS-1$
        int tabWidth = fTextLayout.getBounds().width;
        fTextLayout.setTabs(new int[] { tabWidth });
        fTextLayout.setText(""); //$NON-NLS-1$
    }

    /*
     * @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim()
     */
    @Override
    public Rectangle computeTrim() {
        Rectangle trim = super.computeTrim();
        if (isResizable()) {
            boolean RTL = (getShell().getStyle() & SWT.RIGHT_TO_LEFT) != 0;
            if (RTL) {
                trim.x -= fgScrollBarSize.x;
            }
            trim.width += fgScrollBarSize.x;
            trim.height += fgScrollBarSize.y;
        }
        return trim;
    }

    /**
     * Adds the listener to the collection of listeners who will be notified when the current location has changed or is
     * about to change.
     * 
     * @param listener
     *            the location listener
     * @since 3.4
     */
    @Override
    public void addLocationListener(LocationListener listener) {
        fBrowser.addLocationListener(listener);
    }

    /*
     * @see IInformationControlExtension#hasContents()
     */
    @Override
    public boolean hasContents() {
        return fBrowserHasContent;
    }

    /**
     * Adds a listener for input changes to this input change provider. Has no effect if an identical listener is
     * already registered.
     * 
     * @param inputChangeListener
     *            the listener to add
     * @since 3.4
     */
    @Override
    public void addInputChangeListener(IInputChangedListener inputChangeListener) {
        Assert.isNotNull(inputChangeListener);
        fInputChangeListeners.add(inputChangeListener);
    }

    /**
     * Removes the given input change listener from this input change provider. Has no effect if an identical listener
     * is not registered.
     * 
     * @param inputChangeListener
     *            the listener to remove
     * @since 3.4
     */
    public void removeInputChangeListener(IInputChangedListener inputChangeListener) {
        fInputChangeListeners.remove(inputChangeListener);
    }

    /*
     * @see org.eclipse.jface.text.IDelayedInputChangeProvider#setDelayedInputChangeListener(org.eclipse.jface.text.IInputChangedListener)
     * @since 3.4
     */
    @Override
    public void setDelayedInputChangeListener(IInputChangedListener inputChangeListener) {
        fDelayedInputChangeListener = inputChangeListener;
    }

    /**
     * Tells whether a delayed input change listener is registered.
     * 
     * @return <code>true</code> if a delayed input change listener is currently registered
     * @since 3.4
     */
    @Override
    public boolean hasDelayedInputChangeListener() {
        return fDelayedInputChangeListener != null;
    }

    /**
     * Notifies listeners of a delayed input change.
     * 
     * @param newInput
     *            the new input, or <code>null</code> to request cancellation
     * @since 3.4
     */
    @Override
    public void notifyDelayedInputChange(Object newInput) {
        if (fDelayedInputChangeListener != null)
            fDelayedInputChangeListener.inputChanged(newInput);
    }

    /*
     * @see java.lang.Object#toString()
     * @since 3.4
     */
    @Override
    public String toString() {
        String style = (getShell().getStyle() & SWT.RESIZE) == 0 ? "fixed" : "resizeable"; //$NON-NLS-1$ //$NON-NLS-2$
        return super.toString() + " -  style: " + style; //$NON-NLS-1$
    }

}