diff options
Diffstat (limited to 'libjava/classpath/java/awt/LightweightDispatcher.java')
| -rw-r--r-- | libjava/classpath/java/awt/LightweightDispatcher.java | 165 |
1 files changed, 138 insertions, 27 deletions
diff --git a/libjava/classpath/java/awt/LightweightDispatcher.java b/libjava/classpath/java/awt/LightweightDispatcher.java index 8606464..7e33bd4 100644 --- a/libjava/classpath/java/awt/LightweightDispatcher.java +++ b/libjava/classpath/java/awt/LightweightDispatcher.java @@ -38,8 +38,6 @@ exception statement from your version. */ package java.awt; -import gnu.java.awt.AWTUtilities; - import java.awt.event.MouseEvent; import java.util.WeakHashMap; @@ -67,6 +65,13 @@ class LightweightDispatcher * as well as the MOUSE_RELEASED event following the dragging. */ private Component dragTarget; + + /** + * Stores the button number which started the drag operation. This is needed + * because we want to handle only one drag operation and only the button that + * started the dragging should be able to stop it (by a button release). + */ + private int dragButton; /** * The last mouse event target. If the target changes, additional @@ -121,15 +126,41 @@ class LightweightDispatcher /** * Handles all mouse events that are targetted at toplevel containers * (Window instances) and dispatches them to the correct lightweight child. - * + * * @param ev the mouse event * @return whether or not we found a lightweight that handled the event. */ private boolean handleMouseEvent(MouseEvent ev) { Window window = (Window) ev.getSource(); - Component target = window.findComponentAt(ev.getX(), ev.getY()); - target = findTarget(target); + // Find the target for the mouse event. We first seach the deepest + // component at the specified location. The we go up to its parent and + // try to find a neighbor of the deepest component that is suitable as + // mouse event target (it must be showing, at that location and have either + // a MouseListener or MouseMotionListener installed). If no such component + // is found, then we walk up the container hierarchy and find the next + // container that has a MouseListener or MouseMotionListener installed. + Component deepest = window.findComponentAt(ev.getX(), ev.getY()); + if (deepest == null) + return false; + Container parent = deepest.getParent(); + Point loc = ev.getPoint(); + loc = convertPointToChild(window, loc, parent); + Component target = null; + if (parent != null) + { + target = findTarget(parent, loc); + while (target == null && parent != null) + { + if (parent.getMouseListeners().length > 0 + || parent.getMouseMotionListeners().length > 0) + { + target = parent; + } + else + parent = parent.getParent(); + } + } if (target == null || target.isLightweight()) { // Dispatch additional MOUSE_EXITED and MOUSE_ENTERED if event target @@ -138,18 +169,26 @@ class LightweightDispatcher { if (lastTarget != null) { - Point p1 = AWTUtilities.convertPoint(window, ev.getX(), - ev.getY(), lastTarget); + Point p1 = convertPointToChild(window, ev.getPoint(), + lastTarget); MouseEvent mouseExited = new MouseEvent(lastTarget, MouseEvent.MOUSE_EXITED, ev.getWhen(), ev.getModifiers(), p1.x, p1.y, ev.getClickCount(), ev.isPopupTrigger()); lastTarget.dispatchEvent(mouseExited); } - if (target != null) + + // If a target exists dispatch the MOUSE_ENTERED event only if + // there is currently no component from which a drag operation + // started (dragTarget == null) or the target is that component + // (dragTarget == target) + // That way a user can click and hold on a button (putting it into + // the armed state), move the cursor above other buttons without + // affecting their rollover state and get back to the initial + // button. + if (target != null && (dragTarget == null || dragTarget == target)) { - Point p = AWTUtilities.convertPoint(window, ev.getX(), ev.getY(), - target); + Point p = convertPointToChild(window, ev.getPoint(), target); MouseEvent mouseEntered = new MouseEvent(target, MouseEvent.MOUSE_ENTERED, ev.getWhen(), ev.getModifiers(), p.x, p.y, ev.getClickCount(), @@ -161,12 +200,30 @@ class LightweightDispatcher switch (ev.getID()) { case MouseEvent.MOUSE_PRESSED: - dragTarget = target; + // Handle the start of a drag operation or discard the event if + // one is already in progress. This prevents focus changes with the + // other mouse buttons when one is used for dragging. + if (dragTarget == null) + { + lastTarget = dragTarget = target; + + // Save the button that started the drag operation. + dragButton = ev.getButton(); + } + else + return false; + break; case MouseEvent.MOUSE_RELEASED: - if (dragTarget != null) - target = dragTarget; - dragTarget = null; + // Stop the drag operation only when the button that started + // it was released. + if (dragTarget != null && dragButton == ev.getButton()) + { + target = dragTarget; + dragTarget = null; + } + + lastTarget = target; break; case MouseEvent.MOUSE_CLICKED: // When we receive a MOUSE_CLICKED, we set the target to the @@ -174,27 +231,35 @@ class LightweightDispatcher // This is necessary for the case when the MOUSE_RELEASED has // caused the original target (like an internal component) go // away. + // This line is the reason why it is not possible to move the + // 'lastTarget = target' assignment before the switch-statement. target = lastTarget; break; case MouseEvent.MOUSE_DRAGGED: + // We consider only dragTarget for redispatching the event still + // we have to act in a way that the newly found target component + // was handled. + lastTarget = target; target = dragTarget; break; default: - // Do nothing in other cases. + // Only declare current target as the old value in all other + // cases. + lastTarget = target; break; } - lastTarget = target; - if (target != null) { - Point targetCoordinates = - AWTUtilities.convertPoint(window, ev.getX(), ev.getY(), target); + Point targetCoordinates = convertPointToChild(window, + ev.getPoint(), + target); int dx = targetCoordinates.x - ev.getX(); int dy = targetCoordinates.y - ev.getY(); ev.translatePoint(dx, dy); ev.setSource(target); target.dispatchEvent(ev); + // We reset the event, so that the normal event dispatching is not // influenced by this modified event. ev.setSource(window); @@ -209,20 +274,66 @@ class LightweightDispatcher /** * Finds the actual target for a mouseevent, starting at <code>c</code>. - * This searches upwards the component hierarchy until it finds a component - * that has a mouselistener attached. + * This searches through the children of the container and finds the first + * one which is showing, at the location from the mouse event and has + * a MouseListener or MouseMotionListener attached. If no such child component + * is found, null is returned. * - * @param c the component to start searching from + * @param c the container to search through + * @param loc the mouse event point * - * @return the actual receiver of the mouse event + * @return the actual receiver of the mouse event, or null, if no such + * component has been found */ - private Component findTarget(Component c) + private Component findTarget(Container c, Point loc) { - Component target = c; - while (target != null && target.getMouseListeners().length == 0) + Component[] children = c.getComponents(); + Component target = null; + if (c != null) { - target = target.getParent(); + for (int i = 0; i < children.length; i++) + { + Component child = children[i]; + if (child.isShowing()) + { + if (child.contains(loc.x - child.getX(), loc.y - child.getY()) + && (child.getMouseListeners().length > 0 + || child.getMouseMotionListeners().length > 0)) + { + target = child; + break; + } + } + } } return target; } + + /** + * Converts a point in the parent's coordinate system to a child coordinate + * system. The resulting point is stored in the same Point object and + * returned. + * + * @param parent the parent component + * @param p the point + * @param child the child component + * + * @return the translated point + */ + private Point convertPointToChild(Component parent, Point p, + Component child) + { + int offX = 0; + int offY = 0; + Component comp = child; + while (comp != null && comp != parent) + { + offX += comp.getX(); + offY += comp.getY(); + comp = comp.getParent(); + } + p.x -= offX; + p.y -= offY; + return p; + } } |