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

Java tutorial

Introduction

Here is the source code for org.eclipse.swt.widgets.TaskItem.java

Source

/*******************************************************************************
 * Copyright (c) 2000, 2016 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
 *     Tasktop Technologies - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.win32.*;

/**
 * Instances of this class represent a task item.
 *
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 *
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 *
 * @since 3.6
 *
 * @noextend This class is not intended to be subclassed by clients.
 */
public class TaskItem extends Item {
    TaskBar parent;
    Shell shell;
    int progress, progressState = SWT.DEFAULT;
    Image overlayImage;
    String overlayText = "";
    boolean showingText = false;
    Menu menu;

    static final int PROGRESS_MAX = 100;

    /**
     * Constructs a new instance of this class given its parent
     * (which must be a <code>Tray</code>) and a style value
     * describing its behavior and appearance. The item is added
     * to the end of the items maintained by its parent.
     * <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
     * @see Widget#checkSubclass
     * @see Widget#getStyle
     */
    TaskItem(TaskBar parent, int style) {
        super(parent, style);
        this.parent = parent;
        parent.createItem(this, -1);
    }

    @Override
    protected void checkSubclass() {
        if (!isValidSubclass())
            error(SWT.ERROR_INVALID_SUBCLASS);
    }

    @Override
    void destroyWidget() {
        parent.destroyItem(this);
        releaseHandle();
    }

    /**
     * Returns the receiver's pop up menu if it has one, or null
     * if it does not.
     *
     * @return the receiver's menu
     *
     * @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>
     */
    @Override
    public Menu getMenu() {
        checkWidget();
        return menu;
    }

    /**
     * Returns the receiver's overlay image if it has one, or null
     * if it does not.
     *
     * @return the receiver's overlay 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 getOverlayImage() {
        checkWidget();
        return overlayImage;
    }

    /**
     * Returns the receiver's overlay text, which will be an empty
     * string if it has never been set.
     *
     * @return the receiver's overlay 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 getOverlayText() {
        checkWidget();
        return overlayText;
    }

    /**
     * Returns the receiver's parent, which must be a <code>TaskBar</code>.
     *
     * @return the receiver's parent
     *
     * @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 TaskBar getParent() {
        checkWidget();
        return parent;
    }

    /**
     * Returns the receiver's progress.
     *
     * @return the receiver's progress
     *
     * @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 getProgress() {
        checkWidget();
        return progress;
    }

    /**
     * Returns the receiver's progress state.
     *
     * @return the receiver's progress state
     *
     * @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 getProgressState() {
        checkWidget();
        return progressState;
    }

    void recreate() {
        if (showingText) {
            if (overlayText.length() != 0)
                updateText();
        } else {
            if (overlayImage != null)
                updateImage();
        }
        if (progress != 0)
            updateProgress();
        if (progressState != SWT.DEFAULT)
            updateProgressState();
    }

    @Override
    void releaseHandle() {
        super.releaseHandle();
        parent = null;
    }

    @Override
    void releaseWidget() {
        super.releaseWidget();
        overlayImage = null;
        overlayText = null;
    }

    /**
     * Sets the receiver's pop up menu to the argument. The way the menu is
     * shown is platform specific.
     *
     * <p>
     * This feature might not be available for the receiver on all
     * platforms. The application code can check if it is supported
     * by calling the respective get method. When the feature is not
     * available, the get method will always return the NULL.</p>
     *
     * <p>
     * For better cross platform support, the application code should
     * set this feature on the <code>TaskItem</code> for application.<br>
     * On Windows, this feature will only work on RCP applications.</p>
     *
     * <p>
     * The menu should be fully created before this method is called.
     * Dynamic changes to the menu after the method is called will not be reflected
     * in the native menu.</p>
     *
     * @param menu the new pop up menu
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_MENU_NOT_POP_UP - the menu is not a pop up menu</li>
     *    <li>ERROR_INVALID_ARGUMENT - if the menu 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 setMenu(Menu menu) {
        checkWidget();
        if (menu != null) {
            if (menu.isDisposed())
                error(SWT.ERROR_INVALID_ARGUMENT);
            if ((menu.style & SWT.POP_UP) == 0) {
                error(SWT.ERROR_MENU_NOT_POP_UP);
            }
        }
        if (shell != null)
            return;
        this.menu = menu;
        parent.setMenu(menu);
    }

    /**
     * Sets the receiver's overlay image, which may be null
     * indicating that no image should be displayed. The bounds
     * for the overlay image is determined by the platform and in
     * general it should be a small image.
     *
     * <p>
     * This feature might not be available for the receiver on all
     * platforms. The application code can check if it is supported
     * by calling the respective get method. When the feature is not
     * available, the get method will always return the NULL.</p>
     *
     * <p>
     * For better cross platform support, the application code should
     * first try to set this feature on the <code>TaskItem</code> for the
     * main shell then on the <code>TaskItem</code> for the application.</p>
     *
     * @param overlayImage the new overlay image (may be null)
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_INVALID_ARGUMENT - if the overlayImage 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 setOverlayImage(Image overlayImage) {
        checkWidget();
        if (overlayImage != null && overlayImage.isDisposed())
            error(SWT.ERROR_INVALID_ARGUMENT);
        if (shell == null)
            return;
        this.overlayImage = overlayImage;
        if (overlayImage != null) {
            updateImage();
        } else {
            if (overlayText.length() != 0) {
                updateText();
            } else {
                parent.mTaskbarList3.SetOverlayIcon(shell.handle, 0, 0);
            }
        }
    }

    /**
     * Sets the receiver's overlay text. The space available to display the
     * overlay text is platform dependent and in general it should be no longer
     * than a few characters.
     *
     * <p>
     * This feature might not be available for the receiver on all
     * platforms. The application code can check if it is supported
     * by calling the respective get method. When the feature is not
     * available, the get method will always return an empty string.</p>
     *
     * <p>
     * For better cross platform support, the application code should
     * first try to set this feature on the <code>TaskItem</code> for the
     * main shell then on the <code>TaskItem</code> for the application.</p>
     *
     * @param overlayText the new overlay text
     *
     * @exception IllegalArgumentException <ul>
     *    <li>ERROR_NULL_ARGUMENT - if the overlayText 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 setOverlayText(String overlayText) {
        checkWidget();
        if (overlayText == null)
            error(SWT.ERROR_NULL_ARGUMENT);
        if (shell == null)
            return;
        this.overlayText = overlayText;
        if (overlayText.length() != 0) {
            updateText();
        } else {
            if (overlayImage != null) {
                updateImage();
            } else {
                parent.mTaskbarList3.SetOverlayIcon(shell.handle, 0, 0);
            }
        }
    }

    /**
     * Sets the receiver's progress, the progress represents a percentage and
     * should be in range from 0 to 100. The progress is only shown when the progress
     * state is different than <code>SWT#DEFAULT</code>.
     *
     * <p>
     * This feature might not be available for the receiver on all
     * platforms. The application code can check if it is supported
     * by calling the respective get method. When the feature is not
     * available, the get method will always return zero.</p>
     *
     * <p>
     * For better cross platform support, the application code should
     * first try to set this feature on the <code>TaskItem</code> for the
     * main shell then on the <code>TaskItem</code> for the application.</p>
     *
     * @param progress the new progress
     *
     * @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>
     *
     * #see {@link #setProgressState(int)}
     */
    public void setProgress(int progress) {
        checkWidget();
        if (shell == null)
            return;
        progress = Math.max(0, Math.min(progress, PROGRESS_MAX));
        if (this.progress == progress)
            return;
        this.progress = progress;
        updateProgress();
    }

    /**
     * Sets the receiver's progress state, the state can be one of
     * the following:
     * <ul>
     * <li>{@link SWT#DEFAULT}</li>
     * <li>{@link SWT#NORMAL}</li>
     * <li>{@link SWT#PAUSED}</li>
     * <li>{@link SWT#ERROR}</li>
     * <li>{@link SWT#INDETERMINATE}</li>
     * </ul>
     *
     * The percentage of progress shown by the states <code>SWT#NORMAL</code>, <code>SWT#PAUSED</code>,
     * <code>SWT#ERROR</code> is set with <code>setProgress()</code>. <br>
     * The state <code>SWT#DEFAULT</code> indicates that no progress should be shown.
     *
     * <p>
     * This feature might not be available for the receiver on all
     * platforms. The application code can check if it is supported
     * by calling the respective get method. When the feature is not
     * available, the get method will always return <code>SWT#DEFAULT</code>.</p>
     *
     * <p>
     * For better cross platform support, the application code should
     * first try to set this feature on the <code>TaskItem</code> for the
     * main shell then on the <code>TaskItem</code> for the application.</p>
     *
     * @param progressState the new progress state
     *
     * @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>
     *
     * #see {@link #setProgress(int)}
     */
    public void setProgressState(int progressState) {
        checkWidget();
        if (shell == null)
            return;
        if (this.progressState == progressState)
            return;
        this.progressState = progressState;
        updateProgressState();
    }

    void setShell(Shell shell) {
        this.shell = shell;
        shell.addListener(SWT.Dispose, new Listener() {
            @Override
            public void handleEvent(Event event) {
                if (isDisposed())
                    return;
                dispose();
            }
        });
    }

    void updateImage() {
        showingText = false;
        Image image2 = null;
        long hIcon = 0;
        switch (overlayImage.type) {
        case SWT.BITMAP:
            image2 = Display.createIcon(overlayImage);
            hIcon = image2.handle;
            break;
        case SWT.ICON:
            hIcon = overlayImage.handle;
            break;
        }
        parent.mTaskbarList3.SetOverlayIcon(shell.handle, hIcon, 0);
        if (image2 != null)
            image2.dispose();
    }

    void updateProgress() {
        if (progressState == SWT.INDETERMINATE)
            return;
        if (progressState == SWT.DEFAULT)
            return;
        parent.mTaskbarList3.SetProgressValue(shell.handle, progress, PROGRESS_MAX);
    }

    void updateProgressState() {
        int tbpFlags = OS.TBPF_NOPROGRESS;
        switch (progressState) {
        case SWT.NORMAL:
            tbpFlags = OS.TBPF_NORMAL;
            break;
        case SWT.ERROR:
            tbpFlags = OS.TBPF_ERROR;
            break;
        case SWT.PAUSED:
            tbpFlags = OS.TBPF_PAUSED;
            break;
        case SWT.INDETERMINATE:
            tbpFlags = OS.TBPF_INDETERMINATE;
            break;
        }
        parent.mTaskbarList3.SetProgressValue(shell.handle, progress, PROGRESS_MAX);
        parent.mTaskbarList3.SetProgressState(shell.handle, tbpFlags);
    }

    void updateText() {
        showingText = true;
        /* Create resources */
        int width = 16, height = 16;
        long hdc = OS.GetDC(0);
        BITMAPINFOHEADER bmiHeader = new BITMAPINFOHEADER();
        bmiHeader.biSize = BITMAPINFOHEADER.sizeof;
        bmiHeader.biWidth = width;
        bmiHeader.biHeight = -height;
        bmiHeader.biPlanes = 1;
        bmiHeader.biBitCount = 32;
        bmiHeader.biCompression = OS.BI_RGB;
        byte[] bmi = new byte[BITMAPINFOHEADER.sizeof];
        OS.MoveMemory(bmi, bmiHeader, BITMAPINFOHEADER.sizeof);
        long[] pBits = new long[1];
        long hBitmap = OS.CreateDIBSection(0, bmi, OS.DIB_RGB_COLORS, pBits, 0, 0);
        if (hBitmap == 0)
            error(SWT.ERROR_NO_HANDLES);
        long dstHdc = OS.CreateCompatibleDC(hdc);
        long oldBitmap = OS.SelectObject(dstHdc, hBitmap);
        long hMask = OS.CreateBitmap(width, height, 1, 1, null);
        if (hMask == 0)
            error(SWT.ERROR_NO_HANDLES);
        long maskHdc = OS.CreateCompatibleDC(hdc);
        long oldMask = OS.SelectObject(maskHdc, hMask);

        /* Draw content */
        OS.PatBlt(maskHdc, 0, 0, width, height, OS.WHITENESS);
        long oldBrush = OS.SelectObject(maskHdc, OS.GetStockObject(OS.BLACK_BRUSH));
        OS.RoundRect(maskHdc, 0, 0, width, height, 8, 8);
        OS.SelectObject(maskHdc, oldBrush);

        long brush = OS.CreateSolidBrush(OS.GetSysColor(OS.COLOR_HIGHLIGHT));
        oldBrush = OS.SelectObject(dstHdc, brush);
        OS.RoundRect(dstHdc, 0, 0, width, height, 8, 8);
        OS.SelectObject(dstHdc, oldBrush);
        OS.DeleteObject(brush);

        int uFormat = OS.DT_LEFT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
        RECT rect = new RECT();
        char[] buffer = overlayText.toCharArray();
        int length = buffer.length;
        long hFont = 0, oldHFont = 0;
        NONCLIENTMETRICS info = new NONCLIENTMETRICS();
        info.cbSize = NONCLIENTMETRICS.sizeof;
        if (OS.SystemParametersInfo(OS.SPI_GETNONCLIENTMETRICS, 0, info, 0)) {
            LOGFONT logFont = info.lfMessageFont;
            logFont.lfHeight = -10;
            hFont = OS.CreateFontIndirect(logFont);
            oldHFont = OS.SelectObject(dstHdc, hFont);
            OS.DrawText(dstHdc, buffer, length, rect, uFormat | OS.DT_CALCRECT);
            if (rect.right > width - 2) {
                OS.SelectObject(dstHdc, oldHFont);
                OS.DeleteObject(hFont);
                logFont.lfHeight = -8;
                hFont = OS.CreateFontIndirect(logFont);
                OS.SelectObject(dstHdc, hFont);
            }
        }
        OS.DrawText(dstHdc, buffer, length, rect, uFormat | OS.DT_CALCRECT);
        OS.OffsetRect(rect, (width - rect.right) / 2, (height - rect.bottom) / 2);
        int oldBkMode = OS.SetBkMode(dstHdc, OS.TRANSPARENT);
        OS.SetTextColor(dstHdc, OS.GetSysColor(OS.COLOR_HIGHLIGHTTEXT));
        OS.DrawText(dstHdc, buffer, length, rect, uFormat);
        if (hFont != 0) {
            OS.SelectObject(dstHdc, oldHFont);
            OS.DeleteObject(hFont);
        }
        OS.SetBkMode(dstHdc, oldBkMode);

        /* Release resources */
        OS.SelectObject(dstHdc, oldBitmap);
        OS.DeleteDC(dstHdc);
        OS.SelectObject(maskHdc, oldMask);
        OS.DeleteDC(maskHdc);
        OS.ReleaseDC(0, hdc);

        ICONINFO iconInfo = new ICONINFO();
        iconInfo.fIcon = true;
        iconInfo.hbmColor = hBitmap;
        iconInfo.hbmMask = hMask;
        long hIcon = OS.CreateIconIndirect(iconInfo);
        if (hIcon == 0)
            error(SWT.ERROR_NO_HANDLES);
        OS.DeleteObject(hBitmap);
        OS.DeleteObject(hMask);

        parent.mTaskbarList3.SetOverlayIcon(shell.handle, hIcon, 0);
        OS.DestroyIcon(hIcon);
    }

}