Java tutorial
/******************************************************************************* * 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.events.*; import org.eclipse.swt.graphics.*; import org.eclipse.swt.internal.*; import org.eclipse.swt.internal.gtk.*; /** * Instances of the receiver represent a selectable user interface object * that allows the user to drag a rubber banded outline of the sash within * the parent control. * <dl> * <dt><b>Styles:</b></dt> * <dd>HORIZONTAL, VERTICAL, SMOOTH</dd> * <dt><b>Events:</b></dt> * <dd>Selection</dd> * </dl> * <p> * Note: Only one of the styles HORIZONTAL and VERTICAL 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/#sash">Sash 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 Sash extends Control { boolean dragging; int startX, startY, lastX, lastY; long defaultCursor; private final static int INCREMENT = 1; private final static int PAGE_INCREMENT = 9; /** * 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#HORIZONTAL * @see SWT#VERTICAL * @see SWT#SMOOTH * @see Widget#checkSubclass * @see Widget#getStyle */ public Sash(Composite parent, int style) { super(parent, checkStyle(style)); } /** * Adds the listener to the collection of listeners who will * be notified when the control is selected by the user, by sending * it one of the messages defined in the <code>SelectionListener</code> * interface. * <p> * When <code>widgetSelected</code> is called, the x, y, width, and height fields of the event object are valid. * If the receiver is being dragged, the event object detail field contains the value <code>SWT.DRAG</code>. * <code>widgetDefaultSelected</code> is not called. * </p> * * @param listener the listener which should be notified when the control is selected by the user * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener 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> * * @see SelectionListener * @see #removeSelectionListener * @see SelectionEvent */ public void addSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) error(SWT.ERROR_NULL_ARGUMENT); TypedListener typedListener = new TypedListener(listener); addListener(SWT.Selection, typedListener); addListener(SWT.DefaultSelection, typedListener); } static int checkStyle(int style) { style |= SWT.SMOOTH; return checkBits(style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0); } @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; int border = getBorderWidthInPixels(); int width = border * 2, height = border * 2; if ((style & SWT.HORIZONTAL) != 0) { width += DEFAULT_WIDTH; height += 3; } else { width += 3; height += DEFAULT_HEIGHT; } if (wHint != SWT.DEFAULT) width = wHint + (border * 2); if (hHint != SWT.DEFAULT) height = hHint + (border * 2); return new Point(width, height); } @Override void createHandle(int index) { state |= HANDLE | THEME_BACKGROUND; handle = OS.g_object_new(display.gtk_fixed_get_type(), 0); if (handle == 0) error(SWT.ERROR_NO_HANDLES); gtk_widget_set_has_surface_or_window(handle, true); GTK.gtk_widget_set_can_focus(handle, true); if ((style & SWT.VERTICAL) != 0) { if (GTK.GTK4) { byte[] name = Converter.wcsToMbcs("w-resize", true); defaultCursor = GDK.gdk_cursor_new_from_name(name, 0); } else { defaultCursor = GDK.gdk_cursor_new_for_display(GDK.gdk_display_get_default(), GDK.GDK_SB_H_DOUBLE_ARROW); } } else { if (GTK.GTK4) { byte[] name = Converter.wcsToMbcs("ns-resize", true); defaultCursor = GDK.gdk_cursor_new_from_name(name, 0); } else { defaultCursor = GDK.gdk_cursor_new_for_display(GDK.gdk_display_get_default(), GDK.GDK_SB_V_DOUBLE_ARROW); } } } void drawBand(int x, int y, int width, int height) { if ((style & SWT.SMOOTH) != 0) return; } @Override long gtk_button_press_event(long widget, long event) { long result = super.gtk_button_press_event(widget, event); if (result != 0) return result; // Event fields int[] eventButton = new int[1]; GDK.gdk_event_get_button(event, eventButton); int eventType = GDK.gdk_event_get_event_type(event); double[] eventRX = new double[1]; double[] eventRY = new double[1]; GDK.gdk_event_get_root_coords(event, eventRX, eventRY); int eventTime = GDK.gdk_event_get_time(event); int button = eventButton[0]; if (button != 1) return 0; if (eventType == GDK.GDK_2BUTTON_PRESS) return 0; if (eventType == GDK.GDK_3BUTTON_PRESS) return 0; long window = gtk_widget_get_window(widget); int[] origin_x = new int[1], origin_y = new int[1]; GDK.gdk_window_get_origin(window, origin_x, origin_y); startX = (int) (eventRX[0] - origin_x[0]); startY = (int) (eventRY[0] - origin_y[0]); GtkAllocation allocation = new GtkAllocation(); GTK.gtk_widget_get_allocation(handle, allocation); int x = allocation.x; int y = allocation.y; int width = allocation.width; int height = allocation.height; lastX = x; lastY = y; Event jEvent = new Event(); jEvent.time = eventTime; Rectangle eventRect = new Rectangle(lastX, lastY, width, height); jEvent.setBounds(DPIUtil.autoScaleDown(eventRect)); if ((style & SWT.SMOOTH) == 0) { jEvent.detail = SWT.DRAG; } if ((parent.style & SWT.MIRRORED) != 0) jEvent.x = DPIUtil.autoScaleDown(parent.getClientWidth() - width) - jEvent.x; sendSelectionEvent(SWT.Selection, jEvent, true); if (isDisposed()) return 0; if (jEvent.doit) { dragging = true; Rectangle rect = DPIUtil.autoScaleUp(jEvent.getBounds()); lastX = rect.x; lastY = rect.y; if ((parent.style & SWT.MIRRORED) != 0) lastX = parent.getClientWidth() - width - lastX; parent.update(true, (style & SWT.SMOOTH) == 0); drawBand(lastX, rect.y, width, height); if ((style & SWT.SMOOTH) != 0) { setBoundsInPixels(rect.x, rect.y, width, height); // widget could be disposed at this point } } return result; } @Override long gtk_button_release_event(long widget, long event) { long result = super.gtk_button_release_event(widget, event); if (result != 0) return result; int[] eventButton = new int[1]; GDK.gdk_event_get_button(event, eventButton); int eventTime = GDK.gdk_event_get_time(event); int button = eventButton[0]; if (button != 1) return 0; if (!dragging) return 0; dragging = false; GtkAllocation allocation = new GtkAllocation(); GTK.gtk_widget_get_allocation(handle, allocation); int width = allocation.width; int height = allocation.height; Event jEvent = new Event(); jEvent.time = eventTime; Rectangle eventRect = new Rectangle(lastX, lastY, width, height); jEvent.setBounds(DPIUtil.autoScaleDown(eventRect)); drawBand(lastX, lastY, width, height); if ((parent.style & SWT.MIRRORED) != 0) jEvent.x = DPIUtil.autoScaleDown(parent.getClientWidth() - width) - jEvent.x; sendSelectionEvent(SWT.Selection, jEvent, true); if (isDisposed()) return result; if (jEvent.doit) { if ((style & SWT.SMOOTH) != 0) { Rectangle rect = DPIUtil.autoScaleUp(jEvent.getBounds()); setBoundsInPixels(rect.x, rect.y, width, height); // widget could be disposed at this point } } return result; } @Override long gtk_draw(long widget, long cairo) { if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) { long context = GTK.gtk_widget_get_style_context(widget); GtkAllocation allocation = new GtkAllocation(); GTK.gtk_widget_get_allocation(widget, allocation); int width = (state & ZERO_WIDTH) != 0 ? 0 : allocation.width; int height = (state & ZERO_HEIGHT) != 0 ? 0 : allocation.height; // We specify a 0 value for x & y as we want the whole widget to be // colored, not some portion of it. GTK.gtk_render_background(context, cairo, 0, 0, width, height); } return super.gtk_draw(widget, cairo); } @Override long gtk_focus_in_event(long widget, long event) { long result = super.gtk_focus_in_event(widget, event); if (result != 0) return result; // widget could be disposed at this point if (handle != 0) { GtkAllocation allocation = new GtkAllocation(); GTK.gtk_widget_get_allocation(handle, allocation); lastX = allocation.x; lastY = allocation.y; } return 0; } @Override long gtk_key_press_event(long widget, long eventPtr) { long result = super.gtk_key_press_event(widget, eventPtr); if (result != 0) return result; int[] key = new int[1]; GDK.gdk_event_get_keyval(eventPtr, key); int[] state = new int[1]; GDK.gdk_event_get_state(eventPtr, state); switch (key[0]) { case GDK.GDK_Left: case GDK.GDK_Right: case GDK.GDK_Up: case GDK.GDK_Down: int xChange = 0, yChange = 0; int stepSize = PAGE_INCREMENT; if ((state[0] & GDK.GDK_CONTROL_MASK) != 0) stepSize = INCREMENT; if ((style & SWT.VERTICAL) != 0) { if (key[0] == GDK.GDK_Up || key[0] == GDK.GDK_Down) break; xChange = key[0] == GDK.GDK_Left ? -stepSize : stepSize; } else { if (key[0] == GDK.GDK_Left || key[0] == GDK.GDK_Right) break; yChange = key[0] == GDK.GDK_Up ? -stepSize : stepSize; } int parentBorder = 0; GtkAllocation allocation = new GtkAllocation(); GTK.gtk_widget_get_allocation(handle, allocation); int width = allocation.width; int height = allocation.height; GTK.gtk_widget_get_allocation(parent.handle, allocation); int parentWidth = allocation.width; int parentHeight = allocation.height; int newX = lastX, newY = lastY; if ((style & SWT.VERTICAL) != 0) { newX = Math.min(Math.max(0, lastX + xChange - parentBorder - startX), parentWidth - width); } else { newY = Math.min(Math.max(0, lastY + yChange - parentBorder - startY), parentHeight - height); } if (newX == lastX && newY == lastY) return result; /* Ensure that the pointer image does not change */ long gdkResource = GTK.GTK4 ? gtk_widget_get_surface(handle) : gtk_widget_get_window(handle); int grabMask = GDK.GDK_POINTER_MOTION_MASK | GDK.GDK_BUTTON_RELEASE_MASK; long gdkCursor = cursor != null ? cursor.handle : defaultCursor; int ptrGrabResult = gdk_pointer_grab(gdkResource, GDK.GDK_OWNERSHIP_NONE, false, grabMask, gdkResource, gdkCursor, GDK.GDK_CURRENT_TIME); /* The event must be sent because its doit flag is used. */ Event event = new Event(); event.time = GDK.gdk_event_get_time(eventPtr); Rectangle eventRect = new Rectangle(newX, newY, width, height); event.setBounds(DPIUtil.autoScaleDown(eventRect)); if ((parent.style & SWT.MIRRORED) != 0) event.x = DPIUtil.autoScaleDown(parent.getClientWidth() - width) - event.x; sendSelectionEvent(SWT.Selection, event, true); if (ptrGrabResult == GDK.GDK_GRAB_SUCCESS) gdk_pointer_ungrab(gdkResource, GDK.GDK_CURRENT_TIME); if (isDisposed()) break; if (event.doit) { Rectangle rect = DPIUtil.autoScaleUp(event.getBounds()); lastX = rect.x; lastY = rect.y; if ((parent.style & SWT.MIRRORED) != 0) lastX = parent.getClientWidth() - width - lastX; if ((style & SWT.SMOOTH) != 0) { setBoundsInPixels(rect.x, rect.y, width, height); if (isDisposed()) break; } int cursorX = rect.x, cursorY = rect.y; if ((style & SWT.VERTICAL) != 0) { cursorY += height / 2; } else { cursorX += width / 2; } display.setCursorLocation(parent.toDisplayInPixels(cursorX, cursorY)); } break; } return result; } @Override long gtk_motion_notify_event(long widget, long eventPtr) { long result = super.gtk_motion_notify_event(widget, eventPtr); if (result != 0) return result; if (!dragging) return 0; int eventX, eventY, eventState; double[] fetchedX = new double[1]; double[] fetchedY = new double[1]; GDK.gdk_event_get_root_coords(eventPtr, fetchedX, fetchedY); int[] state = new int[1]; GDK.gdk_event_get_state(eventPtr, state); long gdkResource = gdk_event_get_surface_or_window(eventPtr); boolean isHint; if (GTK.GTK4) { isHint = false; } else { GdkEventMotion gdkEvent = new GdkEventMotion(); OS.memmove(gdkEvent, eventPtr, GdkEventMotion.sizeof); isHint = gdkEvent.is_hint != 0; } if (isHint) { int[] pointer_x = new int[1], pointer_y = new int[1], mask = new int[1]; display.gdk_window_get_device_position(gdkResource, pointer_x, pointer_y, mask); eventX = pointer_x[0]; eventY = pointer_y[0]; eventState = mask[0]; } else { int[] origin_x = new int[1], origin_y = new int[1]; if (GTK.GTK4) { GDK.gdk_surface_get_origin(gdkResource, origin_x, origin_y); } else { GDK.gdk_window_get_origin(gdkResource, origin_x, origin_y); } eventX = (int) (fetchedX[0] - origin_x[0]); eventY = (int) (fetchedY[0] - origin_y[0]); eventState = state[0]; } if ((eventState & GDK.GDK_BUTTON1_MASK) == 0) return 0; GtkAllocation allocation = new GtkAllocation(); GTK.gtk_widget_get_allocation(handle, allocation); int x = allocation.x; int y = allocation.y; int width = allocation.width; int height = allocation.height; int parentBorder = 0; GTK.gtk_widget_get_allocation(parent.handle, allocation); int parentWidth = allocation.width; int parentHeight = allocation.height; int newX = lastX, newY = lastY; if ((style & SWT.VERTICAL) != 0) { newX = Math.min(Math.max(0, eventX + x - startX - parentBorder), parentWidth - width); } else { newY = Math.min(Math.max(0, eventY + y - startY - parentBorder), parentHeight - height); } if (newX == lastX && newY == lastY) return 0; drawBand(lastX, lastY, width, height); Event event = new Event(); event.time = GDK.gdk_event_get_time(eventPtr); Rectangle eventRect = new Rectangle(newX, newY, width, height); event.setBounds(DPIUtil.autoScaleDown(eventRect)); if ((style & SWT.SMOOTH) == 0) { event.detail = SWT.DRAG; } if ((parent.style & SWT.MIRRORED) != 0) event.x = DPIUtil.autoScaleDown(parent.getClientWidth() - width) - event.x; sendSelectionEvent(SWT.Selection, event, true); if (isDisposed()) return 0; Rectangle rect = DPIUtil.autoScaleUp(event.getBounds()); if (event.doit) { lastX = rect.x; lastY = rect.y; if ((parent.style & SWT.MIRRORED) != 0) lastX = parent.getClientWidth() - width - lastX; } parent.update(true, (style & SWT.SMOOTH) == 0); drawBand(lastX, lastY, width, height); if ((style & SWT.SMOOTH) != 0) { /* * Use lastX instead of rect.x, as lastX takes into account * the event.doit flag. See bug 522140. */ setBoundsInPixels(lastX, lastY, width, height); // widget could be disposed at this point } return result; } @Override long gtk_realize(long widget) { setCursor(cursor != null ? cursor.handle : 0); return super.gtk_realize(widget); } @Override void hookEvents() { super.hookEvents(); GTK.gtk_widget_add_events(handle, GDK.GDK_POINTER_MOTION_HINT_MASK); } @Override void releaseWidget() { super.releaseWidget(); if (defaultCursor != 0) OS.g_object_unref(defaultCursor); defaultCursor = 0; } /** * Removes the listener from the collection of listeners who will * be notified when the control is selected by the user. * * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException <ul> * <li>ERROR_NULL_ARGUMENT - if the listener 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> * * @see SelectionListener * @see #addSelectionListener */ public void removeSelectionListener(SelectionListener listener) { checkWidget(); if (listener == null) error(SWT.ERROR_NULL_ARGUMENT); if (eventTable == null) return; eventTable.unhook(SWT.Selection, listener); eventTable.unhook(SWT.DefaultSelection, listener); } @Override void setCursor(long cursor) { super.setCursor(cursor != 0 ? cursor : defaultCursor); } @Override int traversalCode(int key, long event) { return 0; } }