Display an ellipse on the screen

Question

TahoeSands 0 Light Poster

13 Years Ago

Normally, I post all the information and code snippets that I can muster when asking a question, but this time I will throw "caution to the wind" and just pose the scenario/question...

Right now there is an application running and displayed on my screen, the Firefox Web Browser. I want to display an ellipse, of a particular size and color, in a particular location on the screen in front of me. I want to do this in order to "highlight" the "DANIWEB" logo, BUT I do not want to interact with the Web Browser itself.

The way I would describe what I want to do is this... I want to create an "overlay" of an ellipse "border".

I do not want a dialog or any other form of "box" to be displayed along with this ellipse shape. I ONLY want to ellipse to appear over the background. I suppose this might be and "ellipse layer" displayed over a "background layer".

Anything spring to mind?

java

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JamesCherrill 4,733 Most Valuable Poster

13 Years Ago

Since Java 1.6.(something) there has been an implementation of transparent windows, which lets you display window content (eg text or shapes such as elipses) without the window itself being visible. It's going to be a full feature in Java 1.7, but right now you have to know where to look for it.
I wrote the following to check it all out under Win7 - it doesn't exactly do what you want, but it should give you the additional pieces you need...

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Shape;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.lang.reflect.Method;

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


public class DemoWindows implements ActionListener {

   public static void main(String[] args) {
      // create a new demo, and update it every 50 mSec
      new Timer(50, new DemoWindows()).start();
   }

   int phase = 0; // demo runs a number of consecutive phases
   int count = 0; // each of which takes a number of timesteps

   JFrame window1 = new JFrame("Java windows demo");
   JLabel text1 = new JLabel("<HTML><H1>This is a demo of some of the effects"
         + "<BR>that can be achieved with the new Java"
         + "<BR>transparent window methods</H1>"
         + "<BR>(requires latest version of Java)");
   JFrame window2 = new JFrame("Java windows demo");
   JLabel text2 = new JLabel("<HTML><center>Java<BR>rocks");

   int w, h, r, x, y; // parameters of iris circle

   DemoWindows() {

      // build and diplay the windows
      window1.add(text1);
      window1.pack();
      centerOnScreen(window1);
      window1.setVisible(true);

      window2.setUndecorated(true);
      setTransparent(window2);
      setAlpha(window2, 0.0f);

      text2.setFont(new Font("Arial", 1, 60));
      text2.setForeground(Color.red);

      window2.add(text2);
      window2.pack();
      centerOnScreen(window2);
      window2.setVisible(true);

      // parameters of the smallest circle that encloses window2
      // this is the starting pouint for the "iris out" effect
      w = window2.getWidth();
      h = window2.getHeight();
      r = (int) Math.sqrt(w * w + h * h) / 2; // radius
      x = w / 2 - r; // top left coordinates of circle
      y = h / 2 - r;

   }

   @Override
   public void actionPerformed(ActionEvent e) {
      // called by timer 20 times per sec
      // goes thru a number of phases, each a few seconds long
      switch (phase) {
      case 0: {
         // initial pause
         if (++count > 50) {
            phase = 1; // go to next phase
            count = 0;
         }
         break;
      }
      case 1: {
         // fade in
         if (++count < 100) {
            setAlpha(window2, 0.01f * count);
         } else {
            phase = 2; // go to next phase
            count = 0;
         }
         break;
      }
      case 2: {
         // move
         if (++count < 160) {
            if (count < 28 || count > 80) // pause for best effect
               window2.setLocation(window2.getX() + 1, window2.getY() + 1);
         } else {
            phase = 3; // go to next phase
            count = 0;
         }
         break;
      }
      case 3: {
         // iris out
         if (++count < r) {
            Shape shape = new Ellipse2D.Double(x + count, y + count, 2 * (r - count),
                  2 * (r - count));
            setShape(window2, shape);
         } else {
            phase = 99; // go to final (exit) phase
         }
         break;
      }
      case 99:
         System.exit(0);
      }

   }

   void centerOnScreen(JFrame window) { // convenience method
      Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
      window.setLocation((screenSize.width - window.getWidth()) / 2,
            (screenSize.height - window.getHeight()) / 2);
   }

   // here's the magic:

   private boolean usingAwtUtilities = true;
   private Class<?> awtUtilitiesClass = null;
   private Method mSetWindowOpaque, mSetWindowOpacity, mSetWindowShape;

   void initReflection() {
      if (System.getProperty("java.version").startsWith("1.6")) {
         // Sun doc recommends accessing awtUtilities stuff via Reflection
         // (presumably to avoid access restriction rules)
         try {
            awtUtilitiesClass = Class.forName("com.sun.awt.AWTUtilities");
            mSetWindowOpaque = awtUtilitiesClass.getMethod("setWindowOpaque",
                  Window.class, boolean.class);
            mSetWindowOpacity = awtUtilitiesClass.getMethod("setWindowOpacity",
                  Window.class, float.class);
            mSetWindowShape = awtUtilitiesClass.getMethod("setWindowShape", Window.class,
                  Shape.class);
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else { // no need to do anything for 1.7 and later
         usingAwtUtilities = false;
      }
   }

   void setTransparent(JFrame window) {
      // cover for temporary API expected to change for Java 7
      if (usingAwtUtilities && awtUtilitiesClass == null) initReflection();
      if (usingAwtUtilities) {
         try {
            mSetWindowOpaque.invoke(null, window, Boolean.valueOf(false));
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else {
         window.setBackground(new Color(0, 0, 0, 0));
         // Under 1.7 using an alpha <1 sets opaque to flase
      }
      window.getRootPane().setOpaque(false);
   }

   void setAlpha(JFrame window, float alpha) {
      // cover for temporary API expected to change for Java 7
      if (usingAwtUtilities && awtUtilitiesClass == null) initReflection();
      if (usingAwtUtilities) {
         try {
            mSetWindowOpacity.invoke(null, window, Float.valueOf(alpha));
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else {  
         // window.setOpacity(alpha);  // needs Java 1.7 to compile
      }
   }

   void setShape(JFrame window, Shape shape) {
      // cover for temporary API expected to change for Java 7
      if (usingAwtUtilities && awtUtilitiesClass == null) initReflection();
      if (usingAwtUtilities) {
         try {
            mSetWindowShape.invoke(null, window, shape);
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else {
         // window.setShape(shape);   // needs Java 1.7 to compile
      }
   }

}

Try running it and let me know how it works for you

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TahoeSands 0 Light Poster · Answer 1 · 2010-09-07T21:35:26+00:00

Since Java 1.6.(something) there has been an implementation of transparent windows, which lets you display window content (eg text or shapes such as elipses) without the window itself being visible. It's going to be a full feature in Java 1.7, but right now you have to know where to look for it.
I wrote the following to check it all out under Win7 - it doesn't exactly do what you want, but it should give you the additional pieces you need...

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Shape;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.lang.reflect.Method;

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


public class DemoWindows implements ActionListener {

   public static void main(String[] args) {
      // create a new demo, and update it every 50 mSec
      new Timer(50, new DemoWindows()).start();
   }

   int phase = 0; // demo runs a number of consecutive phases
   int count = 0; // each of which takes a number of timesteps

   JFrame window1 = new JFrame("Java windows demo");
   JLabel text1 = new JLabel("<HTML><H1>This is a demo of some of the effects"
         + "<BR>that can be achieved with the new Java"
         + "<BR>transparent window methods</H1>"
         + "<BR>(requires latest version of Java)");
   JFrame window2 = new JFrame("Java windows demo");
   JLabel text2 = new JLabel("<HTML><center>Java<BR>rocks");

   int w, h, r, x, y; // parameters of iris circle

   DemoWindows() {

      // build and diplay the windows
      window1.add(text1);
      window1.pack();
      centerOnScreen(window1);
      window1.setVisible(true);

      window2.setUndecorated(true);
      setTransparent(window2);
      setAlpha(window2, 0.0f);

      text2.setFont(new Font("Arial", 1, 60));
      text2.setForeground(Color.red);

      window2.add(text2);
      window2.pack();
      centerOnScreen(window2);
      window2.setVisible(true);

      // parameters of the smallest circle that encloses window2
      // this is the starting pouint for the "iris out" effect
      w = window2.getWidth();
      h = window2.getHeight();
      r = (int) Math.sqrt(w * w + h * h) / 2; // radius
      x = w / 2 - r; // top left coordinates of circle
      y = h / 2 - r;

   }

   @Override
   public void actionPerformed(ActionEvent e) {
      // called by timer 20 times per sec
      // goes thru a number of phases, each a few seconds long
      switch (phase) {
      case 0: {
         // initial pause
         if (++count > 50) {
            phase = 1; // go to next phase
            count = 0;
         }
         break;
      }
      case 1: {
         // fade in
         if (++count < 100) {
            setAlpha(window2, 0.01f * count);
         } else {
            phase = 2; // go to next phase
            count = 0;
         }
         break;
      }
      case 2: {
         // move
         if (++count < 160) {
            if (count < 28 || count > 80) // pause for best effect
               window2.setLocation(window2.getX() + 1, window2.getY() + 1);
         } else {
            phase = 3; // go to next phase
            count = 0;
         }
         break;
      }
      case 3: {
         // iris out
         if (++count < r) {
            Shape shape = new Ellipse2D.Double(x + count, y + count, 2 * (r - count),
                  2 * (r - count));
            setShape(window2, shape);
         } else {
            phase = 99; // go to final (exit) phase
         }
         break;
      }
      case 99:
         System.exit(0);
      }

   }

   void centerOnScreen(JFrame window) { // convenience method
      Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
      window.setLocation((screenSize.width - window.getWidth()) / 2,
            (screenSize.height - window.getHeight()) / 2);
   }

   // here's the magic:

   private boolean usingAwtUtilities = true;
   private Class<?> awtUtilitiesClass = null;
   private Method mSetWindowOpaque, mSetWindowOpacity, mSetWindowShape;

   void initReflection() {
      if (System.getProperty("java.version").startsWith("1.6")) {
         // Sun doc recommends accessing awtUtilities stuff via Reflection
         // (presumably to avoid access restriction rules)
         try {
            awtUtilitiesClass = Class.forName("com.sun.awt.AWTUtilities");
            mSetWindowOpaque = awtUtilitiesClass.getMethod("setWindowOpaque",
                  Window.class, boolean.class);
            mSetWindowOpacity = awtUtilitiesClass.getMethod("setWindowOpacity",
                  Window.class, float.class);
            mSetWindowShape = awtUtilitiesClass.getMethod("setWindowShape", Window.class,
                  Shape.class);
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else { // no need to do anything for 1.7 and later
         usingAwtUtilities = false;
      }
   }

   void setTransparent(JFrame window) {
      // cover for temporary API expected to change for Java 7
      if (usingAwtUtilities && awtUtilitiesClass == null) initReflection();
      if (usingAwtUtilities) {
         try {
            mSetWindowOpaque.invoke(null, window, Boolean.valueOf(false));
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else {
         window.setBackground(new Color(0, 0, 0, 0));
         // Under 1.7 using an alpha <1 sets opaque to flase
      }
      window.getRootPane().setOpaque(false);
   }

   void setAlpha(JFrame window, float alpha) {
      // cover for temporary API expected to change for Java 7
      if (usingAwtUtilities && awtUtilitiesClass == null) initReflection();
      if (usingAwtUtilities) {
         try {
            mSetWindowOpacity.invoke(null, window, Float.valueOf(alpha));
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else {  
         // window.setOpacity(alpha);  // needs Java 1.7 to compile
      }
   }

   void setShape(JFrame window, Shape shape) {
      // cover for temporary API expected to change for Java 7
      if (usingAwtUtilities && awtUtilitiesClass == null) initReflection();
      if (usingAwtUtilities) {
         try {
            mSetWindowShape.invoke(null, window, shape);
         } catch (Exception e) {
            e.printStackTrace();
         }
      } else {
         // window.setShape(shape);   // needs Java 1.7 to compile
      }
   }

}

Try running it and let me know how it works for you

Sweet! It works nicely and it seems to have most all the elements I will need to solve my dilemma.

Thanks for the guide James.

JamesCherrill 4,733 Most Valuable Poster Team Colleague Featured Poster · Answer 2 · 2010-09-07T21:41:07+00:00

JamesCherrill 4,733 Most Valuable Poster

13 Years Ago

Just for my info, what OS and version did you test it on?

TahoeSands 0 Light Poster · Answer 3 · 2010-09-08T02:43:51+00:00

Just for my info, what OS and version did you test it on?

Win7

Display an ellipse on the screen

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