org.eclipse.swt.widgets.Label.java Source code

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/*******************************************************************************
 * Copyright (c) 2000, 2018 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.swt.widgets;

import org.eclipse.swt.*;
import org.eclipse.swt.accessibility.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;

/**
 * Instances of this class represent a non-selectable
 * user interface object that displays a string or image.
 * When SEPARATOR is specified, displays a single
 * vertical or horizontal line.
 * <p>
 * Shadow styles are hints and may not be honored
 * by the platform.  To create a separator label
 * with the default shadow style for the platform,
 * do not specify a shadow style.
 * </p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SEPARATOR, HORIZONTAL, VERTICAL</dd>
 * <dd>SHADOW_IN, SHADOW_OUT, SHADOW_NONE</dd>
 * <dd>CENTER, LEFT, RIGHT, WRAP</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * Note: Only one of SHADOW_IN, SHADOW_OUT and SHADOW_NONE may be specified.
 * SHADOW_NONE is a HINT. Only one of HORIZONTAL and VERTICAL may be specified.
 * Only one of CENTER, LEFT and RIGHT may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 *
 * @see <a href="http://www.eclipse.org/swt/snippets/#label">Label snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 * @noextend This class is not intended to be subclassed by clients.
 */
public class Label extends Control {
    long frameHandle, labelHandle, imageHandle, boxHandle;
    ImageList imageList;
    Image image;
    String text;

    /**
     * Constructs a new instance of this class given its parent
     * and a style value describing its behavior and appearance.
     * <p>
     * The style value is either one of the style constants defined in
     * class <code>SWT</code> which is applicable to instances of this
     * class, or must be built by <em>bitwise OR</em>'ing together
     * (that is, using the <code>int</code> "|" operator) two or more
     * of those <code>SWT</code> style constants. The class description
     * lists the style constants that are applicable to the class.
     * Style bits are also inherited from superclasses.
     * </p>
     *
     * @param parent a composite control which will be the parent of the new instance (cannot be null)
     * @param style the style of control to construct
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
     *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
     * </ul>
     *
     * @see SWT#SEPARATOR
     * @see SWT#HORIZONTAL
     * @see SWT#VERTICAL
     * @see SWT#SHADOW_IN
     * @see SWT#SHADOW_OUT
     * @see SWT#SHADOW_NONE
     * @see SWT#CENTER
     * @see SWT#LEFT
     * @see SWT#RIGHT
     * @see SWT#WRAP
     * @see Widget#checkSubclass
     * @see Widget#getStyle
     */
    public Label(Composite parent, int style) {
        super(parent, checkStyle(style));
    }

    static int checkStyle(int style) {
        style |= SWT.NO_FOCUS;
        if ((style & SWT.SEPARATOR) != 0) {
            style = checkBits(style, SWT.VERTICAL, SWT.HORIZONTAL, 0, 0, 0, 0);
            return checkBits(style, SWT.SHADOW_OUT, SWT.SHADOW_IN, SWT.SHADOW_NONE, 0, 0, 0);
        }
        return checkBits(style, SWT.LEFT, SWT.CENTER, SWT.RIGHT, 0, 0, 0);
    }

    @Override
    void addRelation(Control control) {
        if (!control.isDescribedByLabel())
            return;
        if (labelHandle == 0)
            return;
        control._getAccessible().addRelation(ACC.RELATION_LABELLED_BY, _getAccessible());
        control.labelRelation = this;
    }

    @Override
    Point computeNativeSize(long h, int wHint, int hHint, boolean changed) {
        int width = wHint, height = hHint;
        /*
         * Feature in GTK3: Labels with long text have an extremely large natural width.
         * As a result, such Labels created with SWT.WRAP end up being too big. The fix
         * is to use the minimum width instead of the natural width when SWT.WRAP is specified.
         * In all other cases, use the natural width. See bug 534768.
         */
        boolean wrap = labelHandle != 0 && (style & SWT.WRAP) != 0 && GTK.gtk_widget_get_visible(labelHandle);
        if (wrap && wHint == SWT.DEFAULT && hHint == SWT.DEFAULT) {
            GtkRequisition naturalSize = new GtkRequisition();
            GtkRequisition minimumSize = new GtkRequisition();
            GTK.gtk_widget_get_preferred_size(h, minimumSize, naturalSize);
            width = minimumSize.width;
            height = naturalSize.height;
            return new Point(width, height);
        } else {
            return super.computeNativeSize(h, wHint, hHint, changed);
        }
    }

    @Override
    Point computeSizeInPixels(int wHint, int hHint, boolean changed) {
        checkWidget();
        if (wHint != SWT.DEFAULT && wHint < 0)
            wHint = 0;
        if (hHint != SWT.DEFAULT && hHint < 0)
            hHint = 0;
        if ((style & SWT.SEPARATOR) != 0) {
            if ((style & SWT.HORIZONTAL) != 0) {
                if (wHint == SWT.DEFAULT)
                    wHint = DEFAULT_WIDTH;
            } else {
                if (hHint == SWT.DEFAULT)
                    hHint = DEFAULT_HEIGHT;
            }
        }
        Point size;
        /*
        * Feature in GTK. GTK has a predetermined maximum width for wrapping text.
        * The fix is to use pango layout directly instead of the label size request
        * to calculate its preferred size.
        */
        boolean fixWrap = labelHandle != 0 && (style & SWT.WRAP) != 0 && GTK.gtk_widget_get_visible(labelHandle);
        if (fixWrap || frameHandle != 0)
            forceResize();
        if (fixWrap) {
            long labelLayout = GTK.gtk_label_get_layout(labelHandle);
            int pangoWidth = OS.pango_layout_get_width(labelLayout);
            if (wHint != SWT.DEFAULT) {
                OS.pango_layout_set_width(labelLayout, wHint * OS.PANGO_SCALE);
            } else {
                OS.pango_layout_set_width(labelLayout, -1);
            }
            int[] w = new int[1], h = new int[1];
            OS.pango_layout_get_pixel_size(labelLayout, w, h);
            OS.pango_layout_set_width(labelLayout, pangoWidth);
            if (frameHandle != 0) {
                int[] labelWidth = new int[1], labelHeight = new int[1];
                GTK.gtk_widget_get_size_request(labelHandle, labelWidth, labelHeight);
                GTK.gtk_widget_set_size_request(labelHandle, 1, 1);
                size = computeNativeSize(frameHandle, -1, -1, changed);
                GTK.gtk_widget_set_size_request(labelHandle, labelWidth[0], labelHeight[0]);
                size.x = size.x - 1;
                size.y = size.y - 1;
            } else {
                size = new Point(0, 0);
            }
            size.x += wHint == SWT.DEFAULT ? w[0] : wHint;
            size.y += hHint == SWT.DEFAULT ? h[0] : hHint;
        } else {
            if (frameHandle != 0) {
                int[] reqWidth = new int[1], reqHeight = new int[1];
                GTK.gtk_widget_get_size_request(handle, reqWidth, reqHeight);
                GTK.gtk_widget_set_size_request(handle, wHint, hHint);
                size = computeNativeSize(frameHandle, -1, -1, changed);
                GTK.gtk_widget_set_size_request(handle, reqWidth[0], reqHeight[0]);
            } else {
                size = computeNativeSize(handle, wHint, hHint, changed);
            }
        }
        /*
        * Feature in GTK.  Instead of using the font height to determine
        * the preferred height of the widget, GTK uses the text metrics.
        * The fix is to ensure that the preferred height is at least as
        * tall as the font height.
        *
        * NOTE: This work around does not fix the case when there are
        * muliple lines of text.
        */
        if (hHint == SWT.DEFAULT && labelHandle != 0) {
            long layout = GTK.gtk_label_get_layout(labelHandle);
            long context = OS.pango_layout_get_context(layout);
            long lang = OS.pango_context_get_language(context);
            long font = getFontDescription();
            long metrics = OS.pango_context_get_metrics(context, font, lang);
            int ascent = OS.PANGO_PIXELS(OS.pango_font_metrics_get_ascent(metrics));
            int descent = OS.PANGO_PIXELS(OS.pango_font_metrics_get_descent(metrics));
            OS.pango_font_metrics_unref(metrics);
            int fontHeight = ascent + descent;
            int[] bufferBottom = new int[1];
            int[] bufferTop = new int[1];
            OS.g_object_get(labelHandle, OS.margin_bottom, bufferBottom, 0);
            OS.g_object_get(labelHandle, OS.margin_top, bufferTop, 0);
            fontHeight += bufferBottom[0] + bufferTop[0];
            if (frameHandle != 0) {
                fontHeight += 2 * getThickness(frameHandle).y;
                fontHeight += 2 * gtk_container_get_border_width_or_margin(frameHandle);
            }
            size.y = Math.max(size.y, fontHeight);
        }
        return size;
    }

    @Override
    void createHandle(int index) {
        state |= HANDLE | THEME_BACKGROUND;
        fixedHandle = OS.g_object_new(display.gtk_fixed_get_type(), 0);
        if (fixedHandle == 0)
            error(SWT.ERROR_NO_HANDLES);
        gtk_widget_set_has_surface_or_window(fixedHandle, true);
        if ((style & SWT.SEPARATOR) != 0) {
            if ((style & SWT.HORIZONTAL) != 0) {
                handle = GTK.gtk_separator_new(GTK.GTK_ORIENTATION_HORIZONTAL);
                if (handle != 0 && GTK.GTK_VERSION >= OS.VERSION(3, 20, 0)) {
                    GTK.gtk_widget_set_valign(handle, GTK.GTK_ALIGN_CENTER);
                }
            } else {
                handle = GTK.gtk_separator_new(GTK.GTK_ORIENTATION_VERTICAL);
                if (handle != 0 && GTK.GTK_VERSION >= OS.VERSION(3, 20, 0)) {
                    GTK.gtk_widget_set_halign(handle, GTK.GTK_ALIGN_CENTER);
                }
            }
            if (handle == 0)
                error(SWT.ERROR_NO_HANDLES);
        } else {
            if (GTK.GTK4) {
                handle = gtk_box_new(GTK.GTK_ORIENTATION_HORIZONTAL, false, 0);
            } else {
                handle = GTK.gtk_event_box_new();
                boxHandle = gtk_box_new(GTK.GTK_ORIENTATION_HORIZONTAL, false, 0);
                if (boxHandle == 0)
                    error(SWT.ERROR_NO_HANDLES);
            }
            if (handle == 0)
                error(SWT.ERROR_NO_HANDLES);
            labelHandle = GTK.gtk_label_new_with_mnemonic(null);
            if (labelHandle == 0)
                error(SWT.ERROR_NO_HANDLES);
            imageHandle = GTK.gtk_image_new();
            if (imageHandle == 0)
                error(SWT.ERROR_NO_HANDLES);
            if (GTK.GTK4) {
                GTK.gtk_container_add(handle, labelHandle);
                GTK.gtk_container_add(handle, imageHandle);
                gtk_box_set_child_packing(handle, labelHandle, true, true, 0, GTK.GTK_PACK_START);
                gtk_box_set_child_packing(handle, imageHandle, true, true, 0, GTK.GTK_PACK_START);
            } else {
                GTK.gtk_container_add(handle, boxHandle);
                GTK.gtk_container_add(boxHandle, labelHandle);
                GTK.gtk_container_add(boxHandle, imageHandle);
                gtk_box_set_child_packing(boxHandle, labelHandle, true, true, 0, GTK.GTK_PACK_START);
                gtk_box_set_child_packing(boxHandle, imageHandle, true, true, 0, GTK.GTK_PACK_START);
            }
        }
        if ((style & SWT.BORDER) != 0) {
            frameHandle = GTK.gtk_frame_new(null);
            if (frameHandle == 0)
                error(SWT.ERROR_NO_HANDLES);
            GTK.gtk_container_add(fixedHandle, frameHandle);
            GTK.gtk_container_add(frameHandle, handle);
            GTK.gtk_frame_set_shadow_type(frameHandle, GTK.GTK_SHADOW_ETCHED_IN);
        } else {
            GTK.gtk_container_add(fixedHandle, handle);
        }
        if ((style & SWT.SEPARATOR) != 0)
            return;
        if ((style & SWT.WRAP) != 0) {
            GTK.gtk_label_set_line_wrap(labelHandle, true);
            GTK.gtk_label_set_line_wrap_mode(labelHandle, OS.PANGO_WRAP_WORD_CHAR);
        }
        // In GTK 3 font description is inherited from parent widget which is not how SWT has always worked,
        // reset to default font to get the usual behavior
        setFontDescription(defaultFont().handle);
        setAlignment();
    }

    @Override
    void createWidget(int index) {
        super.createWidget(index);
        text = "";
    }

    @Override
    void deregister() {
        super.deregister();
        if (frameHandle != 0)
            display.removeWidget(frameHandle);
        if (labelHandle != 0)
            display.removeWidget(labelHandle);
        if (imageHandle != 0)
            display.removeWidget(imageHandle);
        if (boxHandle != 0)
            display.removeWidget(boxHandle);
    }

    @Override
    long eventHandle() {
        return fixedHandle;
    }

    @Override
    long cssHandle() {
        if ((style & SWT.SEPARATOR) == 0) {
            return labelHandle;
        }
        return handle;
    }

    /**
     * Returns a value which describes the position of the
     * text or image in the receiver. The value will be one of
     * <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code>
     * unless the receiver is a <code>SEPARATOR</code> label, in
     * which case, <code>NONE</code> is returned.
     *
     * @return the alignment
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public int getAlignment() {
        checkWidget();
        if ((style & SWT.SEPARATOR) != 0)
            return 0;
        if ((style & SWT.LEFT) != 0)
            return SWT.LEFT;
        if ((style & SWT.CENTER) != 0)
            return SWT.CENTER;
        if ((style & SWT.RIGHT) != 0)
            return SWT.RIGHT;
        return SWT.LEFT;
    }

    @Override
    int getBorderWidthInPixels() {
        checkWidget();
        if (frameHandle != 0) {
            return getThickness(frameHandle).x;
        }
        return 0;
    }

    /**
     * Returns the receiver's image if it has one, or null
     * if it does not.
     *
     * @return the receiver's image
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public Image getImage() {
        checkWidget();
        return image;
    }

    @Override
    String getNameText() {
        return getText();
    }

    /**
     * Returns the receiver's text, which will be an empty
     * string if it has never been set or if the receiver is
     * a <code>SEPARATOR</code> label.
     *
     * @return the receiver's text
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public String getText() {
        checkWidget();
        if ((style & SWT.SEPARATOR) != 0)
            return "";
        return text;
    }

    @Override
    void hookEvents() {
        super.hookEvents();
        if (labelHandle != 0) {
            OS.g_signal_connect_closure_by_id(labelHandle, display.signalIds[MNEMONIC_ACTIVATE], 0,
                    display.getClosure(MNEMONIC_ACTIVATE), false);
        }
    }

    @Override
    boolean isDescribedByLabel() {
        return false;
    }

    @Override
    boolean mnemonicHit(char key) {
        if (labelHandle == 0)
            return false;
        boolean result = super.mnemonicHit(labelHandle, key);
        if (result) {
            Control control = this;
            while (control.parent != null) {
                Control[] children = control.parent._getChildren();
                int index = 0;
                while (index < children.length) {
                    if (children[index] == control)
                        break;
                    index++;
                }
                index++;
                if (index < children.length) {
                    if (children[index].setFocus())
                        return result;
                }
                control = control.parent;
            }
        }
        return result;
    }

    @Override
    boolean mnemonicMatch(char key) {
        if (labelHandle == 0)
            return false;
        return mnemonicMatch(labelHandle, key);
    }

    @Override
    void register() {
        super.register();
        if (boxHandle != 0)
            display.addWidget(boxHandle, this);
        if (frameHandle != 0)
            display.addWidget(frameHandle, this);
        if (labelHandle != 0)
            display.addWidget(labelHandle, this);
        if (imageHandle != 0)
            display.addWidget(imageHandle, this);
    }

    @Override
    void releaseHandle() {
        super.releaseHandle();
        frameHandle = imageHandle = labelHandle = boxHandle = 0;
    }

    @Override
    void releaseWidget() {
        super.releaseWidget();
        if (imageList != null)
            imageList.dispose();
        imageList = null;
        image = null;
        text = null;
    }

    @Override
    void resizeHandle(int width, int height) {
        OS.swt_fixed_resize(GTK.gtk_widget_get_parent(fixedHandle), fixedHandle, width, height);
        long child = frameHandle != 0 ? frameHandle : handle;
        Point sizes = resizeCalculationsGTK3(child, width, height);
        width = sizes.x;
        height = sizes.y;
        OS.swt_fixed_resize(GTK.gtk_widget_get_parent(child), child, width, height);
    }

    /**
     * Controls how text and images will be displayed in the receiver.
     * The argument should be one of <code>LEFT</code>, <code>RIGHT</code>
     * or <code>CENTER</code>.  If the receiver is a <code>SEPARATOR</code>
     * label, the argument is ignored and the alignment is not changed.
     *
     * @param alignment the new alignment
     *
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void setAlignment(int alignment) {
        checkWidget();
        if ((style & SWT.SEPARATOR) != 0)
            return;
        if ((alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER)) == 0)
            return;
        style &= ~(SWT.LEFT | SWT.RIGHT | SWT.CENTER);
        style |= alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER);
        setAlignment();
    }

    void setAlignment() {
        if ((style & SWT.LEFT) != 0) {
            if (GTK.GTK_VERSION >= OS.VERSION(3, 16, 0)) {
                gtk_widget_set_align(labelHandle, GTK.GTK_ALIGN_START, GTK.GTK_ALIGN_START); //Aligns widget
                gtk_label_set_align(0.0f, 0.0f); //Aligns text inside the widget.
                gtk_widget_set_align(imageHandle, GTK.GTK_ALIGN_START, GTK.GTK_ALIGN_CENTER);
            } else {
                GTK.gtk_misc_set_alignment(labelHandle, 0.0f, 0.0f);
                GTK.gtk_misc_set_alignment(imageHandle, 0.0f, 0.5f);
            }
            GTK.gtk_label_set_justify(labelHandle, GTK.GTK_JUSTIFY_LEFT);
            return;
        }
        if ((style & SWT.CENTER) != 0) {
            if (GTK.GTK_VERSION >= OS.VERSION(3, 16, 0)) {
                gtk_widget_set_align(labelHandle, GTK.GTK_ALIGN_CENTER, GTK.GTK_ALIGN_START); //Aligns widget
                gtk_label_set_align(0.5f, 0.0f); //Aligns text inside the widget.
                gtk_widget_set_align(imageHandle, GTK.GTK_ALIGN_CENTER, GTK.GTK_ALIGN_CENTER);
            } else {
                GTK.gtk_misc_set_alignment(labelHandle, 0.5f, 0.0f);
                GTK.gtk_misc_set_alignment(imageHandle, 0.5f, 0.5f);
            }

            GTK.gtk_label_set_justify(labelHandle, GTK.GTK_JUSTIFY_CENTER);
            return;
        }
        if ((style & SWT.RIGHT) != 0) {
            if (GTK.GTK_VERSION >= OS.VERSION(3, 16, 0)) {
                gtk_widget_set_align(labelHandle, GTK.GTK_ALIGN_END, GTK.GTK_ALIGN_START); //Aligns widget.
                gtk_label_set_align(1.0f, 0.0f); //Aligns text inside the widget.
                gtk_widget_set_align(imageHandle, GTK.GTK_ALIGN_END, GTK.GTK_ALIGN_CENTER);
            } else {
                GTK.gtk_misc_set_alignment(labelHandle, 1.0f, 0.0f);
                GTK.gtk_misc_set_alignment(imageHandle, 1.0f, 0.5f);
            }
            GTK.gtk_label_set_justify(labelHandle, GTK.GTK_JUSTIFY_RIGHT);
            return;
        }
    }

    private void gtk_label_set_align(float xalign, float yalign) {
        GTK.gtk_label_set_xalign(labelHandle, xalign);
        GTK.gtk_label_set_yalign(labelHandle, yalign);
    }

    @Override
    int setBounds(int x, int y, int width, int height, boolean move, boolean resize) {
        /*
        * Bug in GTK.  For some reason, when the label is
        * wrappable and its container is resized, it does not
        * cause the label to be wrapped.  The fix is to
        * determine the size that will wrap the label
        * and expilictly set that size to force the label
        * to wrap.
        *
        * This part of the fix causes the label to be
        * resized to the preferred size but it still
        * won't draw properly.
        */
        boolean fixWrap = resize && labelHandle != 0 && (style & SWT.WRAP) != 0;
        if (fixWrap)
            GTK.gtk_widget_set_size_request(labelHandle, -1, -1);
        int result = super.setBounds(x, y, width, height, move, resize);
        /*
        * Bug in GTK.  For some reason, when the label is
        * wrappable and its container is resized, it does not
        * cause the label to be wrapped.  The fix is to
        * determine the size that will wrap the label
        * and expilictly set that size to force the label
        * to wrap.
        *
        * This part of the fix forces the label to be
        * resized so that it will draw wrapped.
        */
        if (fixWrap) {
            GtkAllocation allocation = new GtkAllocation();
            GTK.gtk_widget_get_allocation(handle, allocation);
            int labelWidth = allocation.width;
            int labelHeight = allocation.height;
            GTK.gtk_widget_set_size_request(labelHandle, labelWidth, labelHeight);
            /*
            * Bug in GTK.  Setting the size request should invalidate the label's
            * layout, but it does not.  The fix is to resize the label directly.
            */
            GtkRequisition requisition = new GtkRequisition();
            gtk_widget_get_preferred_size(labelHandle, requisition);
            GTK.gtk_widget_get_allocation(labelHandle, allocation);
            allocation.width = labelWidth;
            allocation.height = labelHeight;
            GTK.gtk_widget_size_allocate(labelHandle, allocation);
        }
        return result;
    }

    @Override
    void setFontDescription(long font) {
        super.setFontDescription(font);
        if (labelHandle != 0)
            setFontDescription(labelHandle, font);
        if (imageHandle != 0)
            setFontDescription(imageHandle, font);

        // Bug 445801: Work around for computeSize not returning a different value after
        // changing font, see https://bugzilla.gnome.org/show_bug.cgi?id=753116
        // This updates the pango context and also clears the size request cache on the GTK side.
        int originalDirection = (style & SWT.RIGHT_TO_LEFT) != 0 ? GTK.GTK_TEXT_DIR_RTL : GTK.GTK_TEXT_DIR_LTR;
        int tempDirection = (style & SWT.RIGHT_TO_LEFT) != 0 ? GTK.GTK_TEXT_DIR_LTR : GTK.GTK_TEXT_DIR_RTL;
        GTK.gtk_widget_set_direction(labelHandle, tempDirection);
        GTK.gtk_widget_set_direction(labelHandle, originalDirection);
    }

    @Override
    void setForegroundGdkRGBA(GdkRGBA rgba) {
        super.setForegroundGdkRGBA(rgba);
        setForegroundGdkRGBA(fixedHandle, rgba);
        if (labelHandle != 0)
            setForegroundGdkRGBA(labelHandle, rgba);
        if (imageHandle != 0)
            setForegroundGdkRGBA(imageHandle, rgba);
    }

    @Override
    void setOrientation(boolean create) {
        super.setOrientation(create);
        if ((style & SWT.RIGHT_TO_LEFT) != 0 || !create) {
            int dir = (style & SWT.RIGHT_TO_LEFT) != 0 ? GTK.GTK_TEXT_DIR_RTL : GTK.GTK_TEXT_DIR_LTR;
            if (labelHandle != 0)
                GTK.gtk_widget_set_direction(labelHandle, dir);
            if (imageHandle != 0)
                GTK.gtk_widget_set_direction(imageHandle, dir);
        }
    }

    /**
     * Sets the receiver's image to the argument, which may be
     * null indicating that no image should be displayed.
     *
     * @param image the image to display on the receiver (may be null)
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void setImage(Image image) {
        checkWidget();
        if (image != null && image.isDisposed()) {
            error(SWT.ERROR_INVALID_ARGUMENT);
        }
        if ((style & SWT.SEPARATOR) != 0)
            return;
        this.image = image;
        if (imageList != null)
            imageList.dispose();
        imageList = null;
        if (image != null) {
            imageList = new ImageList();
            int imageIndex = imageList.add(image);
            long pixbuf = imageList.getPixbuf(imageIndex);
            gtk_image_set_from_gicon(imageHandle, pixbuf);
            GTK.gtk_widget_hide(labelHandle);
            GTK.gtk_widget_show(imageHandle);
        } else {
            gtk_image_set_from_gicon(imageHandle, 0);
            GTK.gtk_widget_show(labelHandle);
            GTK.gtk_widget_hide(imageHandle);
        }
    }

    /**
     * Sets the receiver's text.
     * <p>
     * This method sets the widget label.  The label may include
     * the mnemonic character and line delimiters.
     * </p>
     * <p>
     * Mnemonics are indicated by an '&amp;' that causes the next
     * character to be the mnemonic.  When the user presses a
     * key sequence that matches the mnemonic, focus is assigned
     * to the control that follows the label. On most platforms,
     * the mnemonic appears underlined but may be emphasised in a
     * platform specific manner.  The mnemonic indicator character
     * '&amp;' can be escaped by doubling it in the string, causing
     * a single '&amp;' to be displayed.
     * </p>
     * <p>
     * Note: If control characters like '\n', '\t' etc. are used
     * in the string, then the behavior is platform dependent.
     * </p>
     *
     * @param string the new text
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the text is null</li>
     * </ul>
     * @exception SWTException <ul>
     *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
     *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
     * </ul>
     */
    public void setText(String string) {
        checkWidget();
        if (string == null)
            error(SWT.ERROR_NULL_ARGUMENT);
        if ((style & SWT.SEPARATOR) != 0)
            return;
        text = string;
        char[] chars = fixMnemonic(string);
        byte[] buffer = Converter.wcsToMbcs(chars, true);
        GTK.gtk_label_set_text_with_mnemonic(labelHandle, buffer);
        GTK.gtk_widget_hide(imageHandle);
        GTK.gtk_widget_show(labelHandle);
    }

    @Override
    void setWidgetBackground() {
        if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) {
            GdkRGBA rgba = (state & BACKGROUND) != 0 ? getBackgroundGdkRGBA() : null;
            super.setBackgroundGdkRGBA(handle, rgba);
        } else {
            super.setWidgetBackground();
        }
    }

    @Override
    void showWidget() {
        super.showWidget();
        if (frameHandle != 0)
            GTK.gtk_widget_show(frameHandle);
        if (labelHandle != 0)
            GTK.gtk_widget_show(labelHandle);
        if (boxHandle != 0)
            GTK.gtk_widget_show(boxHandle);
    }

    @Override
    long windowProc(long handle, long arg0, long user_data) {
        /*
         * For Labels/Buttons, the first widget in the tree with a GdkWindow is SwtFixed.
         * Unfortunately this fails the check in !GTK_IS_CONTAINER check Widget.windowProc().
         * Instead lets override windowProc() here and check for paintHandle() compatibility.
         * Fixes bug 481485 without re-introducing bug 483791.
         */
        switch ((int) user_data) {
        case DRAW: {
            if (paintHandle() == handle) {
                return gtk_draw(handle, arg0);
            }
        }
        }
        return super.windowProc(handle, arg0, user_data);
    }
}