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package org.nuiton.jaxx.runtime.swing;
/*
* #%L
* JAXX :: Runtime
* %%
* Copyright (C) 2008 - 2024 Code Lutin, Ultreia.io
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import javax.swing.JComponent;
import javax.swing.SwingUtilities;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.GraphicsEnvironment;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Window;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
/**
* This class allows you to move a Component by using a mouse. The Component
* moved can be a high level Window (ie. Window, Frame, Dialog) in which case
* the Window is moved within the desktop. Or the Component can belong to a
* Container in which case the Component is moved within the Container.
*
* When moving a Window, the listener can be added to a child Component of
* the Window. In this case attempting to move the child will result in the
* Window moving. For example, you might create a custom "Title Bar" for an
* undecorated Window and moving of the Window is accomplished by moving the
* title bar only. Multiple components can be registered as "window movers".
*
* Components can be registered when the class is created. Additional
* components can be added at any time using the registerComponent() method.
*
* @since 2.5.10
*/
public class ComponentMover extends MouseAdapter {
private Insets dragInsets = new Insets(0, 0, 0, 0);
private Dimension snapSize = new Dimension(1, 1);
private Insets edgeInsets = new Insets(0, 0, 0, 0);
private boolean changeCursor = true;
private boolean autoLayout = false;
private Class destinationClass;
private Component destinationComponent;
private Component destination;
private Component source;
private Point pressed;
private Point location;
private Cursor originalCursor;
private boolean autoscrolls;
private boolean potentialDrag;
/**
* Constructor for moving individual components. The components must be
* regisetered using the registerComponent() method.
*/
public ComponentMover() {
}
/**
* Constructor to specify a Class of Component that will be moved when
* drag events are generated on a registered child component. The events
* will be passed to the first ancestor of this specified class.
*
* @param destinationClass the Class of the ancestor component
* @param components the Components to be registered for forwarding
* drag events to the ancestor Component.
*/
public ComponentMover(Class destinationClass, Component... components) {
this.destinationClass = destinationClass;
registerComponent(components);
}
/**
* Constructor to specify a parent component that will be moved when drag
* events are generated on a registered child component.
*
* @param destinationComponent the component drage events should be forwareded to
* @param components the Components to be registered for forwarding drag
* events to the parent component to be moved
*/
public ComponentMover(Component destinationComponent, Component... components) {
this.destinationComponent = destinationComponent;
registerComponent(components);
}
/**
* Get the auto layout property
*
* @return the auto layout property
*/
public boolean isAutoLayout() {
return autoLayout;
}
/**
* Set the auto layout property
*
* @param autoLayout when true layout will be invoked on the parent container
*/
public void setAutoLayout(boolean autoLayout) {
this.autoLayout = autoLayout;
}
/**
* Get the change cursor property
*
* @return the change cursor property
*/
public boolean isChangeCursor() {
return changeCursor;
}
/**
* Set the change cursor property
*
* @param changeCursor when true the cursor will be changed to the
* Cursor.MOVE_CURSOR while the mouse is pressed
*/
public void setChangeCursor(boolean changeCursor) {
this.changeCursor = changeCursor;
}
/**
* Get the drag insets
*
* @return the drag insets
*/
public Insets getDragInsets() {
return dragInsets;
}
/**
* Set the drag insets. The insets specify an area where mouseDragged
* events should be ignored and therefore the component will not be moved.
* This will prevent these events from being confused with a
* MouseMotionListener that supports component resizing.
*
* @param dragInsets
*/
public void setDragInsets(Insets dragInsets) {
this.dragInsets = dragInsets;
}
/**
* Get the bounds insets
*
* @return the bounds insets
*/
public Insets getEdgeInsets() {
return edgeInsets;
}
/**
* Set the edge insets. The insets specify how close to each edge of the parent
* component that the child component can be moved. Positive values means the
* component must be contained within the parent. Negative values means the
* component can be moved outside the parent.
*
* @param edgeInsets
*/
public void setEdgeInsets(Insets edgeInsets) {
this.edgeInsets = edgeInsets;
}
/**
* Remove listeners from the specified component
*
* @param components the component the listeners are removed from
*/
public void deregisterComponent(Component... components) {
for (Component component : components)
component.removeMouseListener(this);
}
/**
* Add the required listeners to the specified component
*
* @param components the component the listeners are added to
*/
public void registerComponent(Component... components) {
for (Component component : components)
component.addMouseListener(this);
}
/**
* Get the snap size
*
* @return the snap size
*/
public Dimension getSnapSize() {
return snapSize;
}
/**
* Set the snap size. Forces the component to be snapped to
* the closest grid position. Snapping will occur when the mouse is
* dragged half way.
*/
public void setSnapSize(Dimension snapSize) {
if (snapSize.width < 1
|| snapSize.height < 1)
throw new IllegalArgumentException("Snap sizes must be greater than 0");
this.snapSize = snapSize;
}
/**
* Setup the variables used to control the moving of the component:
*
* source - the source component of the mouse event
* destination - the component that will ultimately be moved
* pressed - the Point where the mouse was pressed in the destination
* component coordinates.
*/
@Override
public void mousePressed(MouseEvent e) {
source = e.getComponent();
int width = source.getSize().width - dragInsets.left - dragInsets.right;
int height = source.getSize().height - dragInsets.top - dragInsets.bottom;
Rectangle r = new Rectangle(dragInsets.left, dragInsets.top, width, height);
if (r.contains(e.getPoint()))
setupForDragging(e);
}
private void setupForDragging(MouseEvent e) {
source.addMouseMotionListener(this);
potentialDrag = true;
// Determine the component that will ultimately be moved
if (destinationComponent != null) {
destination = destinationComponent;
} else if (destinationClass == null) {
destination = source;
} else // forward events to destination component
{
destination = SwingUtilities.getAncestorOfClass(destinationClass, source);
}
pressed = e.getLocationOnScreen();
location = destination.getLocation();
if (changeCursor) {
originalCursor = source.getCursor();
source.setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
}
// Making sure autoscrolls is false will allow for smoother dragging of
// individual components
if (destination instanceof JComponent) {
JComponent jc = (JComponent) destination;
autoscrolls = jc.getAutoscrolls();
jc.setAutoscrolls(false);
}
}
/**
* Move the component to its new location. The dragged Point must be in
* the destination coordinates.
*/
@Override
public void mouseDragged(MouseEvent e) {
Point dragged = e.getLocationOnScreen();
int dragX = getDragDistance(dragged.x, pressed.x, snapSize.width);
int dragY = getDragDistance(dragged.y, pressed.y, snapSize.height);
int locationX = location.x + dragX;
int locationY = location.y + dragY;
// Mouse dragged events are not generated for every pixel the mouse
// is moved. Adjust the location to make sure we are still on a
// snap value.
while (locationX < edgeInsets.left)
locationX += snapSize.width;
while (locationY < edgeInsets.top)
locationY += snapSize.height;
Dimension d = getBoundingSize(destination);
while (locationX + destination.getSize().width + edgeInsets.right > d.width)
locationX -= snapSize.width;
while (locationY + destination.getSize().height + edgeInsets.bottom > d.height)
locationY -= snapSize.height;
// Adjustments are finished, move the component
destination.setLocation(locationX, locationY);
}
/*
* Determine how far the mouse has moved from where dragging started
* (Assume drag direction is down and right for positive drag distance)
*/
private int getDragDistance(int larger, int smaller, int snapSize) {
int halfway = snapSize / 2;
int drag = larger - smaller;
drag += (drag < 0) ? -halfway : halfway;
drag = (drag / snapSize) * snapSize;
return drag;
}
/*
* Get the bounds of the parent of the dragged component.
*/
private Dimension getBoundingSize(Component source) {
if (source instanceof Window) {
GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
Rectangle bounds = env.getMaximumWindowBounds();
return new Dimension(bounds.width, bounds.height);
} else {
return source.getParent().getSize();
}
}
/** Restore the original state of the Component */
@Override
public void mouseReleased(MouseEvent e) {
if (!potentialDrag) return;
source.removeMouseMotionListener(this);
potentialDrag = false;
if (changeCursor)
source.setCursor(originalCursor);
if (destination instanceof JComponent) {
((JComponent) destination).setAutoscrolls(autoscrolls);
}
// Layout the components on the parent container
if (autoLayout) {
if (destination instanceof JComponent) {
destination.revalidate();
} else {
destination.validate();
}
}
}
}