Java tutorial
/******************************************************************************* * Copyright (c) 2011 Wind River Systems, Inc. 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: * Wind River Systems - initial API and implementation *******************************************************************************/ package org.eclipse.tm.te.ui.swt; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Combo; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Decorations; import org.eclipse.swt.widgets.Group; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Link; import org.eclipse.swt.widgets.List; import org.eclipse.swt.widgets.Scrollable; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Table; import org.eclipse.swt.widgets.Text; import org.eclipse.swt.widgets.Tree; import org.eclipse.ui.PlatformUI; /** * Utility providing convenience methods for use with SWT controls. */ public final class SWTControlUtil { /** * Returns the text from the specified control. The method will return <code>null</code> * if the control is <code>null</code> or has been already disposed. * * @param control The control to get the text from. * @param The text currently set to the control or <code>null</code>. */ public static final String getText(Control control) { if (control != null && !control.isDisposed()) { if (control instanceof Button) { return ((Button) control).getText().trim(); } if (control instanceof Combo) { return ((Combo) control).getText().trim(); } if (control instanceof Group) { return ((Group) control).getText().trim(); } if (control instanceof Label) { return ((Label) control).getText().trim(); } if (control instanceof Link) { return ((Link) control).getText().trim(); } if (control instanceof Text) { return ((Text) control).getText().trim(); } if (control instanceof Decorations) { return ((Decorations) control).getText(); } } return null; } /** * Sets the given text to the specified control. The text will be not applied if the * control is <code>null</code> or has been already disposed or if the given text itself * is <code>null</code>. * * @param control The control the given text should be applied to. * @param value The text to apply to the given control. */ public static final void setText(Control control, String value) { if (control != null && !control.isDisposed() && value != null) { String trimmedValue = value.trim(); // Avoid triggering attached listeners if the value has not changed. String oldValue = getText(control); if (!trimmedValue.equals(oldValue)) { if (control instanceof Button) { ((Button) control).setText(trimmedValue); } if (control instanceof Combo) { ((Combo) control).setText(trimmedValue); } if (control instanceof Group) { ((Group) control).setText(trimmedValue); } if (control instanceof Label) { ((Label) control).setText(trimmedValue); } if (control instanceof Link) { ((Link) control).setText(trimmedValue); } if (control instanceof Text) { ((Text) control).setText(trimmedValue); } if (control instanceof Decorations) { ((Decorations) control).setText(trimmedValue); } } } } /** * Sets the given text to the specified control as tooltip. The tooltip text will be not * applied if the control is <code>null</code> or has been already disposed. * * @param control The control the given text should be applied to. * @param value The text to apply to the given control or <code>null</code> to reset the tooltip. */ public static final void setToolTipText(Control control, String value) { if (control != null && !control.isDisposed()) { control.setToolTipText(value); } } /** * Sets the text of the control (Text, Combo) as tooltip if the text is * not fully visible. * @param control The control to set the tooltip for. */ public static final void setValueToolTip(Scrollable control) { if (control != null && !control.isDisposed()) { String text = null; int resize = 0; if (control instanceof Text) { text = ((Text) control).getText().trim(); resize = control.getBorderWidth() * 2; } if (control instanceof Combo) { text = ((Combo) control).getText().trim(); resize = (int) (control.getSize().y * 1.5) + control.getBorderWidth() * 2; } if (text != null) { GC gc = new GC(control); int width = 0; for (int i = 0; i < text.length(); i++) { width += gc.getAdvanceWidth(text.charAt(i)); } // Show the tooltip _only_ if the text itself exceeds // the length of the control (partially shown within the control). if (width > (control.getClientArea().width - resize)) { control.setToolTipText(text); } else { control.setToolTipText(null); } gc.dispose(); } } } /** * Adds the given text to the specified control. The given text will be added in case it's not * <code>null</code> and not empty and if the given control itself is not <code>null</code> * and not disposed. If the given text is already within the controls drop down list, the text * will <i>not</i> be added again to the list. * * @param control The control to add the given text to. * @param value The text to add to the control. */ public static final void add(Control control, String value) { add(control, value, false); } /** * Adds the given text to the specified control. The given text will be added in case it's not * <code>null</code> and not empty and if the given control itself is not <code>null</code> * and not disposed. If the given text is already within the controls drop down list, the text * will <i>not</i> be added again to the list. * * @param control The control to add the given text to. * @param value The text to add to the control. * @param allowEmpty If <code>true</code>, empty values will be added to the control. Otherwise, * empty values will be filtered out and not applied to the control. */ public static final void add(Control control, String value, boolean allowEmpty) { if (control != null && !control.isDisposed() && value != null) { if (!allowEmpty && value.trim().length() == 0) { return; } if (control instanceof Combo) { Combo combo = ((Combo) control); if (combo.indexOf(value) == -1) { combo.add(value); } } if (control instanceof List) { List list = ((List) control); if (list.indexOf(value) == -1) { list.add(value); } } } } /** * Adds the given text to the specified control at the given index. If the given index is negative, * the item index will be set to <code>0</code>. The given text will be added in case it's not * <code>null</code> and not empty and if the given control itself is not <code>null</code> * and not disposed. If the given text is already within the controls drop down list, the text will * <i>not</i> be added again to the list. * * @param control The control to add the given text to. * @param value The text to add to the control. * @param index The index of the item to add to the control. */ public static final void add(Control control, String value, int index) { add(control, value, index, false); } /** * Adds the given text to the specified control at the given index. If the given index is negative, * the item index will be set to <code>0</code>. The given text will be added in case it's not * <code>null</code> and not empty and if the given control itself is not <code>null</code> * and not disposed. If the given text is already within the controls drop down list, the text will * <i>not</i> be added again to the list. * * @param control The control to add the given text to. * @param value The text to add to the control. * @param index The index of the item to add to the control. * @param allowEmpty If <code>true</code>, empty values will be added to the control. Otherwise, * empty values will be filtered out and not applied to the control. */ public static final void add(Control control, String value, int index, boolean allowEmpty) { if (control != null && !control.isDisposed() && value != null) { if (!allowEmpty && value.trim().length() == 0) { return; } if (control instanceof Combo) { Combo combo = ((Combo) control); if (combo.indexOf(value) == -1) { if (index < 0) { index = 0; } combo.add(value, index); } } if (control instanceof List) { List list = ((List) control); if (list.indexOf(value) == -1) { if (index < 0) { index = 0; } list.add(value, index); } } } } /** * Sets the enabled state of the given control to the given state. The state will be * applied in case the given control is not <code>null</code> and not disposed. * * @param control The control to set the enabled state for. * @param enabled <code>true</code> to enable the control, <code>false</code> otherwise. */ public static final void setEnabled(Control control, boolean enabled) { if (control != null && !control.isDisposed()) { control.setEnabled(enabled); } } /** * Returns the enabled state of the given control. The method returns always <code>true</code> * in case the given control is <code>null</code> or disposed. * * @param control The control to get the enabled state for. * @return <code>true</code> if the control is enabled, <code>false</code> otherwise. */ public static final boolean isEnabled(Control control) { if (control != null && !control.isDisposed()) { return control.isEnabled(); } return true; } /** * Sets the visible state of the given control. The state will be applied in * case the given control is not <code>null</code> and not disposed. * * @param control The control to set the visible state for. * @param visible <code>True</code> to set the control visible, <code>false</code> otherwise. */ public static final void setVisible(Control control, boolean visible) { if (control != null && !control.isDisposed()) { control.setVisible(visible); } } /** * Returns the visible state of the given control. The method returns always * <code>true</code> in case the given control is <code>null</code> or disposed. * * @param control The control to set the visible state for. * @param visible <code>True</code> to set the control visible, <code>false</code> otherwise. */ public static final boolean isVisible(Control control) { if (control != null && !control.isDisposed()) { return control.getVisible(); } return true; } /** * Returns the item count of the specified control. The method will return <code>0</code> * in case the control is <code>null</code> or has been already disposed or does not * support items. * * @param control The control to get the item count for. * @return The number of items within the control or <code>-1</code>. */ public static final int getItemCount(Control control) { if (control != null && !control.isDisposed()) { if (control instanceof Combo) { return ((Combo) control).getItemCount(); } if (control instanceof List) { return ((List) control).getItemCount(); } } return -1; } /** * Sets the specified items to the specified control. * * @param control The control to set the items to. * @param items The array of items to set. */ public static final void setItems(Control control, String[] items) { if (control != null && !control.isDisposed() && items != null) { if (control instanceof Combo) { ((Combo) control).setItems(items); } else if (control instanceof List) { ((List) control).setItems(items); } } } /** * Returns the items of the specified control. The method will return an empty array * in case the control is <code>null</code> or has been already disposed or does not * support items. * * @param control The control to get the items from. * @return The array items or and empty array. */ public static final String[] getItems(Control control) { if (control != null && !control.isDisposed()) { if (control instanceof Combo) { return ((Combo) control).getItems(); } if (control instanceof List) { return ((List) control).getItems(); } } return new String[0]; } /** * Sets the text of the specified item of the specified control. * * @param control The control to set the item text. * @param index The index of the item to change. * @param value The new item text to apply. */ public static final void setItem(Control control, int index, String value) { if (control != null && !control.isDisposed() && value != null) { // The index must be within valid range if (index >= 0 && index < getItemCount(control)) { String trimmedValue = value.trim(); // Avoid triggering attached listeners if the value has not changed. String oldValue = getItem(control, index); if (!trimmedValue.equals(oldValue)) { if (control instanceof Combo) { ((Combo) control).setItem(index, trimmedValue); } if (control instanceof List) { ((List) control).setItem(index, trimmedValue); } } } } } /** * Returns the text of the item at the specified index of the specified control. * * @param control The control to query the item text from. * @param index The index of the item to query. * @return The item text or <code>null</code>. */ public static final String getItem(Control control, int index) { if (control != null && !control.isDisposed()) { // The index must be within valid range if (index >= 0 && index < getItemCount(control)) { if (control instanceof Combo) { return ((Combo) control).getItem(index).trim(); } if (control instanceof List) { return ((List) control).getItem(index).trim(); } } } return null; } /** * Returns the selected item index of the specified control. The method will return <code>-1</code> in case * the control is <code>null</code> or has been already disposed or does not support selections. * * @param control The control to get the selected item index for. * @return The index of the selected item within the control or <code>-1</code>. */ public static final int getSelectionIndex(Control control) { if (control != null && !control.isDisposed()) { if (control instanceof Combo) { return ((Combo) control).getSelectionIndex(); } if (control instanceof List) { return ((List) control).getSelectionIndex(); } if (control instanceof Table) { return ((Table) control).getSelectionIndex(); } } return -1; } /** * Returns the selected item count of the specified control. The method will return <code>-1</code> in case * the control is <code>null</code> or has been already disposed or does not support selections. * * @param control The control to get the selected item count for. * @return The number of selected items within the control or <code>-1</code>. */ public static final int getSelectionCount(Control control) { if (control != null && !control.isDisposed()) { if (control instanceof List) { return ((List) control).getSelectionCount(); } if (control instanceof Table) { return ((Table) control).getSelectionCount(); } if (control instanceof Tree) { return ((Tree) control).getSelectionCount(); } } return -1; } /** * Removes all items of the specified control. * * @param control The control to remove all items from. */ public static final void removeAll(Control control) { if (control != null && !control.isDisposed()) { if (control instanceof Combo) { ((Combo) control).removeAll(); } if (control instanceof List) { ((List) control).removeAll(); } if (control instanceof Table) { ((Table) control).removeAll(); } if (control instanceof Tree) { ((Tree) control).removeAll(); } } } /** * Returns the index of the given item for the specified control. The method will return * <code>-1</code> in case the control is <code>null</code> or has been already disposed * or does not support items. * * @param control The control to lookup the item index. * @param item The item to lookup the index for. * @return The item index if found or <code>-1</code>. */ public static final int indexOf(Control control, String item) { if (control != null && !control.isDisposed() && item != null) { if (control instanceof Combo) { return ((Combo) control).indexOf(item); } if (control instanceof List) { return ((List) control).indexOf(item); } } return -1; } /** * Selects the item with the given item index for the specified control. The method will * return immediately in case the control is <code>null</code> or has been already * disposed or does not support items. * * @param control The control to select the given item. * @param item The item to select. */ public static final void select(Control control, int index) { if (control != null && !control.isDisposed()) { if (index >= 0 && index < getItemCount(control)) { if (control instanceof Combo) { ((Combo) control).select(index); } if (control instanceof List) { ((List) control).select(index); } } } return; } /** * Returns the buttons selection state. * * @param button The button to query the selection state for. * @return <code>true</code> if the button specified is not <code>null</code> nor disposed and selected, <code>false</code> otherwise. */ public static final boolean getSelection(Button button) { if (button != null && !button.isDisposed()) { return button.getSelection(); } return false; } /** * Sets the buttons selection state to the given state. * * @param button The button to set the selection state for. * @param selected The button selection state to set. */ public static final void setSelection(Button button, boolean selected) { if (button != null && !button.isDisposed()) { button.setSelection(selected); } } /** * Returns the number of pixels corresponding to the height of the given * number of characters. * <p> * This methods uses the static {@link Dialog#convertHeightInCharsToPixels(org.eclipse.swt.graphics.FontMetrics, int)} * method for calculation. * <p> * @param chars The number of characters * @return The corresponding height in pixels */ public static int convertHeightInCharsToPixels(Control control, int chars) { int height = 0; if (control != null && !control.isDisposed()) { GC gc = new GC(control); gc.setFont(JFaceResources.getDialogFont()); height = Dialog.convertHeightInCharsToPixels(gc.getFontMetrics(), chars); gc.dispose(); } return height; } /** * Returns the number of pixels corresponding to the width of the given * number of characters. * <p> * This methods uses the static {@link Dialog#convertWidthInCharsToPixels(org.eclipse.swt.graphics.FontMetrics, int)} * method for calculation. * <p> * @param chars The number of characters * @return The corresponding width in pixels */ public static int convertWidthInCharsToPixels(Control control, int chars) { int width = 0; if (control != null && !control.isDisposed()) { GC gc = new GC(control); gc.setFont(JFaceResources.getDialogFont()); width = Dialog.convertWidthInCharsToPixels(gc.getFontMetrics(), chars); gc.dispose(); } return width; } /** * Sets the focus to the given control. * * @param control The control to set the focus to. * @return <code>True</code> if the control got the focus, <code>false</code> otherwise. */ public static boolean setFocus(Control control) { if (control != null && !control.isDisposed()) { return control.setFocus(); } return false; } /** * Sets the given color as control foreground. * * @param control The control. * @param color The color. */ public static void setForeground(Control control, Color color) { if (control != null && !control.isDisposed() && color != null) { control.setForeground(color); } } /** * Sets the given color as control background. * * @param control The control. * @param color The color. */ public static void setBackground(Control control, Color color) { if (control != null && !control.isDisposed() && color != null) { control.setBackground(color); } } /** * Sets the given image as control background image. * * @param control The control. * @param image The image. */ public static void setBackgroundImage(Control control, Image image) { if (control != null && !control.isDisposed() && image != null) { control.setBackgroundImage(image); } } /* -------------------------------------------------------------------- * * Generate system specific checkbox images. * * -------------------------------------------------------------------- */ private static final String CHECKED = "CHECKED"; //$NON-NLS-1$ private static final String UNCHECKED = "UNCHECKED"; //$NON-NLS-1$ private static final String GRAYED = "GRAYED"; //$NON-NLS-1$ private static final String ENABLED = "ENABLED"; //$NON-NLS-1$ private static final String DISABLED = "DISABLED"; //$NON-NLS-1$ private static Image makeShot(Shell shell, boolean checked, boolean grayed, boolean enabled) { shell = new Shell(shell, SWT.NO_FOCUS | SWT.NO_TRIM); Color greenScreen = new Color(shell.getDisplay(), 222, 223, 224); shell.setBackground(greenScreen); Button button = new Button(shell, SWT.CHECK); button.setBackground(greenScreen); button.setSelection(grayed || checked); button.setEnabled(enabled); button.setGrayed(grayed); button.setLocation(0, 0); Point bsize = button.computeSize(SWT.DEFAULT, SWT.DEFAULT); button.setSize(bsize); shell.setSize(bsize); shell.open(); GC gc = new GC(shell); Image image = new Image(shell.getDisplay(), bsize.x, bsize.y); gc.copyArea(image, 0, 0); gc.dispose(); ImageData imageData = image.getImageData(); imageData.transparentPixel = imageData.palette.getPixel(greenScreen.getRGB()); image = new Image(shell.getDisplay(), imageData); shell.close(); return image; } public static synchronized Image getCheckBoxImage(boolean checked, boolean grayed, boolean enabled) { String key = (SWTControlUtil.class.getName() + "_" + //$NON-NLS-1$ ((checked || grayed) ? CHECKED : UNCHECKED) + "_" + //$NON-NLS-1$ (grayed ? GRAYED + "_" : "") + //$NON-NLS-1$ //$NON-NLS-2$ (enabled ? ENABLED : DISABLED)); Image image = JFaceResources.getImageRegistry().get(key); try { if (image == null || image.getImageData().data == null) { Shell shell = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell(); image = makeShot(shell, checked || grayed, grayed, enabled); if (image != null && image.getImageData().data != null) { JFaceResources.getImageRegistry().put(key, image); } } } catch (Exception e) { } return image; } }