Screen edge snapping

    
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;

import javax.swing.JFrame;
import javax.swing.JLabel;

public class WindowSnapper extends ComponentAdapter {

  private boolean locked = false;

  private int sd = 50;

  public void componentMoved(ComponentEvent evt) {
    if (locked)
      return;
    Dimension size = Toolkit.getDefaultToolkit().getScreenSize();
    int nx = evt.getComponent().getX();
    int ny = evt.getComponent().getY();
    // top
    if (ny < 0 + sd) {
      ny = 0;
    }
    // left
    if (nx < 0 + sd) {
      nx = 0;
    }
    // right
    if (nx > size.getWidth() - evt.getComponent().getWidth() - sd) {
      nx = (int) size.getWidth() - evt.getComponent().getWidth();
    }
    // bottom
    if (ny > size.getHeight() - evt.getComponent().getHeight() - sd) {
      ny = (int) size.getHeight() - evt.getComponent().getHeight();
    }
    // make sure we don't get into a recursive loop when the
    // set location generates more events
    locked = true;
    evt.getComponent().setLocation(nx, ny);
    locked = false;
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("");
    JLabel label = new JLabel("Move this window's title bar to demonstrate screen edge snapping.");
    frame.getContentPane().add(label);
    frame.pack();

    frame.addComponentListener(new WindowSnapper());
    frame.setVisible(true);
  }
}

Related examples in the same category

1.	The Swing Version of the Hello, World! Program
2.	Using anonymous inner classes
3.	No direct interaction with JRootPane
4.	A demonstration of the WindowListener approach to closing JFrames
5.	How to center a frame or dialog
6.	React to frame close action
7.	Create a frame
8.	Draw on frame with keyboard
9.	Frame dialog data exchange
10.	Frame with components
11.	Default button for frame: press Enter to activate
12.	Frame Icon drawn by yourself
13.	Create a JFrame class in a thread-safe way
14.	Demo to show a way of having More Choices or Less Choices
15.	Frame Icon from gif
16.	FrameDemo:invoked from the event-dispatching thread
17.	Creating a Borderless Window
18.	Disabling the Close Button on a JFrame
19.	Exiting an Application When a JFrame Is Closed
20.	Use Component listener to ensure frame visibilities
21.	Drag and move a frame from its content area
22.	Setting the Icon for a Frame
23.	Removing the Title Bar of a Frame
24.	Setting the Bounds for a Maximized Frame
25.	Iconifies a frame; the maximized bits are not affected.
26.	Deiconifies a frame; the maximized bits are not affected.
27.	Hiding a Frame When Its Close Button Is Clicked
28.	Exiting an Application When a Frame Is Closed
29.	Getting All Created Frames in an Application
30.	Maximizes a frame; the iconified bit is not affected
31.	Making a Frame Non-Resizable: use setResizable(false) to freeze a frame's size.
32.	Determining When a Frame or Window Is Opened or Closed
33.	Determining When a Frame or Window Is Iconized or Maximized
34.	Determining When a Component Has Been Made Visible, Moved, or Resized
35.	Get the JFrame of a component
36.	Disable JFrame close button
37.	Handle JFrame window events
38.	Define the default close operation of a JFrame to EXIT_ON_CLOSE, application will exit by calling System.exit()
39.	Center a JFrame
40.	Creating Frames with a background image
41.	Preventing a Window from Gaining the Focus
42.	Create undecorated frame
43.	Make a JFrame always visible
44.	Maximize a JFrame
45.	Close a JFrame under condition
46.	Creating a Titleless and Borderless JFrame
47.	FrameDemo2.java shows off the window decoration features added in 1.4
48.	JFrame that closes when someone presses the ESC key
49.	Show the given frame as modal to the specified owner
50.	Set Frame Location By Platform

Screen edge snapping : Frame « Swing JFC « Java

Related examples in the same category