Java tutorial
/******************************************************************************* * Copyright (c) 2002, 2015 Innoopract Informationssysteme GmbH 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: * Innoopract Informationssysteme GmbH - initial API and implementation * EclipseSource - ongoing development ******************************************************************************/ package org.eclipse.swt.widgets; import org.eclipse.rap.rwt.internal.lifecycle.WidgetLCA; import org.eclipse.rap.rwt.internal.theme.ThemeAdapter; import org.eclipse.rap.rwt.theme.BoxDimensions; import org.eclipse.swt.SWT; import org.eclipse.swt.SWTException; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.internal.widgets.progressbarkit.ProgressBarLCA; import org.eclipse.swt.internal.widgets.progressbarkit.ProgressBarThemeAdapter; /** * Instances of the receiver represent is an unselectable user interface object * that is used to display progress, typically in the form of a bar. * <dl> * <dt><b>Styles:</b></dt> * <dd>SMOOTH, HORIZONTAL, VERTICAL, INDETERMINATE</dd> * <dt><b>Events:</b></dt> * <dd>(none)</dd> * </dl> * <p> * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified. * </p> * <p> * IMPORTANT: This class is intended to be subclassed <em>only</em> within the * SWT implementation. * </p> * @since 1.0 */ public class ProgressBar extends Control { private int minimum; private int selection; private int maximum; private int state; /** * 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#SMOOTH * @see SWT#HORIZONTAL * @see SWT#VERTICAL * @see Widget#checkSubclass * @see Widget#getStyle */ public ProgressBar(Composite parent, int style) { super(parent, checkStyle(style)); maximum = 100; state = SWT.NORMAL; } static int checkStyle(int style) { int currStyle = style | SWT.NO_FOCUS; return checkBits(currStyle, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0); } @Override public Point computeSize(int wHint, int hHint, boolean changed) { checkWidget(); BoxDimensions border = getBorder(); int barWidth = getProgressBarWidth(); int width = border.left + border.right; int height = border.top + border.bottom; if ((style & SWT.HORIZONTAL) != 0) { width += barWidth * 10; height += barWidth; } else { width += barWidth; height += barWidth * 10; } if (wHint != SWT.DEFAULT) { width = wHint + border.left + border.right; } if (hHint != SWT.DEFAULT) { height = hHint + border.top + border.bottom; } return new Point(width, height); } /** * Returns the maximum value which the receiver will allow. * * @return the maximum * @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 getMaximum() { checkWidget(); return maximum; } /** * Returns the minimum value which the receiver will allow. * * @return the minimum * @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 getMinimum() { checkWidget(); return minimum; } /** * Returns the single 'selection' that is the receiver's position. * * @return the selection * @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 getSelection() { checkWidget(); return selection; } /** * Sets the maximum value that the receiver will allow. This new value will be * ignored if it is not greater than the receiver's current minimum value. If * the new maximum is applied then the receiver's selection value will be * adjusted if necessary to fall within its new range. * * @param value the new maximum, which must be greater than the current * minimum * @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 setMaximum(int value) { checkWidget(); if (value > getMinimum()) { maximum = value; if (selection > maximum) { selection = maximum; } } } /** * Sets the minimum value that the receiver will allow. This new value will be * ignored if it is negative or is not less than the receiver's current * maximum value. If the new minimum is applied then the receiver's selection * value will be adjusted if necessary to fall within its new range. * * @param value the new minimum, which must be nonnegative and less than the * current maximum * @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 setMinimum(int value) { checkWidget(); if (value > 0 && value < getMaximum()) { minimum = value; if (minimum > selection) { selection = minimum; } } } /** * Sets the single 'selection' that is the receiver's position to the argument * which must be greater than or equal to zero. * * @param value the new selection (must be zero or greater) * @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 setSelection(int value) { checkWidget(); if (value < minimum) { selection = minimum; } else if (value > maximum) { selection = maximum; } else { selection = value; } } /** * Sets the state of the receiver. The state must be one of these values: * <ul> * <li>{@link SWT#NORMAL}</li> * <li>{@link SWT#ERROR}</li> * <li>{@link SWT#PAUSED}</li> * </ul> * * @param state the new 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> * @since 1.3 */ public void setState(int state) { checkWidget(); if (state == SWT.NORMAL || state == SWT.PAUSED || state == SWT.ERROR) { this.state = state; } } /** * Returns the state of the receiver. The value will be one of: * <ul> * <li>{@link SWT#NORMAL}</li> * <li>{@link SWT#ERROR}</li> * <li>{@link SWT#PAUSED}</li> * </ul> * * @return the 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> * @since 1.3 */ public int getState() { checkWidget(); return state; } @Override @SuppressWarnings("unchecked") public <T> T getAdapter(Class<T> adapter) { if (adapter == WidgetLCA.class) { return (T) ProgressBarLCA.INSTANCE; } return super.getAdapter(adapter); } private int getProgressBarWidth() { ThemeAdapter themeAdapter = getAdapter(ThemeAdapter.class); return ((ProgressBarThemeAdapter) themeAdapter).getProgressBarWidth(this); } }