How do I read the status of Caps Lock key?

By Wayan in AWT, Core API 0 Comment

This example show you how to detect if the Caps Lock key is in active mode.

package org.kodejava.awt;

import java.awt.Toolkit;
import java.awt.event.KeyEvent;

public class CapsLockState {
    public static void main(String[] args) {
        // Get the locking state of the Caps Lock button. This method
        // return boolean true value if it is "on".
        boolean isOn = Toolkit.getDefaultToolkit().getLockingKeyState(
                KeyEvent.VK_CAPS_LOCK);

        System.out.println("CapsLock button is " + (isOn ? "on" : "off"));
    }
}

How do I get the number of buttons on the mouse?

By Wayan in AWT, Core API 0 Comment

MouseInfo provides methods for getting information about the mouse, such as mouse pointer location and the number of mouse buttons.

package org.kodejava.awt;

import java.awt.*;

public class MouseNumberOfButtons {
    public static void main(String[] args) {
        // Get the number of buttons on the mouse. On systems without a
        // mouse, returns -1. HeadlessException if
        // GraphicsEnvironment.isHeadless() returns true.
        int numberOfButtons = MouseInfo.getNumberOfButtons();
        System.out.println("Mouse Number Of Buttons = " + numberOfButtons);
    }
}

The output of the code snippet above:

Mouse Number Of Buttons = 5

How do I get the location of mouse pointer?

By Wayan in AWT, Core API 5 Comments

MouseInfo provides methods for getting information about the mouse, such as mouse pointer location and the number of mouse buttons.

package org.kodejava.awt;

import java.awt.*;

public class MouseInfoDemo {
    public static void main(String[] args) {
        int i = 0;
        while (i < 10) {
            // Get the location of our mouse x and y coordinate using
            // the PointerInfo.getLocation() method which return an 
            // instance of Point.
            Point location = MouseInfo.getPointerInfo().getLocation();
            double x = location.getX();
            double y = location.getY();

            System.out.println("x = " + x);
            System.out.println("y = " + y);

            try {
                Thread.sleep(1000);
                i++;
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

How do I get screen’s display mode information?

By Wayan in AWT, Core API 0 Comment

This example shows graphics devices display mode information such as the display width, height, refresh-rate and bit-depth. This information can be obtained from GraphicsDevice.getDisplayMode() method which return an instance of java.awt.DisplayMode.

We can also get the size of a screen using the following example How do I get my screen size?, but this example can handle only a single screen.

package org.kodejava.awt;

import java.awt.*;

public class GettingScreenDisplayModeInformation {
    public static void main(String[] args) {
        // Get local graphics environment
        GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();

        GraphicsDevice[] devices = env.getScreenDevices();

        int sequence = 1;
        for (GraphicsDevice device : devices) {
            System.out.println("Screen Number [" + (sequence++) + "]");
            System.out.println("Width       : " + device.getDisplayMode().getWidth());
            System.out.println("Height      : " + device.getDisplayMode().getHeight());
            System.out.println("Refresh Rate: " + device.getDisplayMode().getRefreshRate());
            System.out.println("Bit Depth   : " + device.getDisplayMode().getBitDepth());
            System.out.println();
        }
    }
}

An example of the program result:

Screen Number [1]
Width       : 2560
Height      : 1080
Refresh Rate: 60
Bit Depth   : 32

Screen Number [2]
Width       : 2560
Height      : 1080
Refresh Rate: 60
Bit Depth   : 32

How do I get number of available screens?

By Wayan in AWT, Core API 0 Comment

This code shows how to get number of available screen devices on the local machine or local graphics environment. We obtain the number of screens by getting the length of array returned by GraphicsEnvironment.getScreenDevices() method.

This process can produce a HeadlessException to happen if we try to run this code on a machine that doesn’t have a screen device with it.

package org.kodejava.awt;

import java.awt.GraphicsEnvironment;
import java.awt.GraphicsDevice;
import java.awt.HeadlessException;

public class GettingNumberOfScreen {
    public static void main(String[] args) {
        try {
            // Get local graphics environment
            GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();

            // Returns an array of all the screen GraphicsDevice objects.
            GraphicsDevice[] devices = env.getScreenDevices();

            int numberOfScreens = devices.length;
            System.out.println("Number of available screens = " + numberOfScreens);
        } catch (HeadlessException e) {
            // We'll get here if no screen devices was found.
            e.printStackTrace();
        }
    }
}

The output of the code snippet above:

Number of available screens = 2