When i get selected text using JNA it returns the Clip Board text

[Hamreen Ahmad]

I have created a project to get the print the selected Text by the user from the global screen when user selects it(by dragging the mouse). 
I have used nativeMousePressed(NativeMouseEvent e) and nativeMouseReleased(NativeMouseEvent e) to detect selecting text from the global screen by using the following lines of code:

    @Override
    public void nativeMousePressed(NativeMouseEvent e) {
        xPress=e.getX();
        yPress=e.getY();
    }


    @Override
    public void nativeMouseReleased(NativeMouseEvent e) {
        xRelease=e.getX();
        yRelease=e.getY();
        if(Math.abs(xPress-xRelease)>0||Math.abs(yPress-yRelease)>0){ //if mouse dragged

            try {
                System.out.println("Selected Text is: "+foo.getSelectedText(foo));
            } catch (Exception e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
        }
    }

so here is the code that gets the selected text
Foo.java

import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.ClipboardOwner;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;

import com.sun.jna.Native;
import com.sun.jna.platform.win32.User32;
import com.sun.jna.platform.win32.WinDef.HWND;
import com.sun.jna.win32.StdCallLibrary;

public class Foo implements ClipboardOwner {

    @Override
    public void lostOwnership(Clipboard clipboard, Transferable contents) {
    }

    public interface CustomUser32 extends StdCallLibrary {
        CustomUser32 INSTANCE = (CustomUser32) Native.loadLibrary("user32", CustomUser32.class);
        HWND GetForegroundWindow();
        void keybd_event(byte bVk, byte bScan, int dwFlags, int dwExtraInfo);
    }

    void controlC(CustomUser32 customUser32) {
        customUser32.keybd_event((byte) 0x11 /* VK_CONTROL*/, (byte) 0, 0, 0);
        customUser32.keybd_event((byte) 0x43 /* 'C' */, (byte) 0, 0, 0);
        customUser32.keybd_event((byte) 0x43 /* 'C' */, (byte) 0, 2 /* KEYEVENTF_KEYUP */, 0);
        customUser32.keybd_event((byte) 0x11 /* VK_CONTROL*/, (byte) 0, 2 /* KEYEVENTF_KEYUP */, 0);// 'Left Control Up
    }

    String getClipboardText() throws Exception {
        try{
            return (String) Toolkit.getDefaultToolkit().getSystemClipboard().getData(DataFlavor.stringFlavor);
        }
        catch(UnsupportedFlavorException e){
            System.out.println("UnsupportedFlavorException: error while transferring data");
            return "";
        }
    }

    void setClipboardText(String data) throws Exception {
        try{
        Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection(data), this);
        }
        catch(IllegalStateException e){
        }
    }

    String getSelectedText(User32 user32, CustomUser32 customUser32) throws Exception {
        HWND hwnd = customUser32.GetForegroundWindow();
        char[] windowText = new char[512];
        user32.GetWindowText(hwnd, windowText, 512);
        String windowTitle = Native.toString(windowText);
        String before = getClipboardText();
        controlC(customUser32); // emulate Ctrl C
        Thread.sleep(100); // give it some time
        String text = getClipboardText();
        setClipboardText(before);
        return text;
    }

    String getWindowTitle(User32 user32, CustomUser32 customUser32) throws Exception {
        HWND hwnd = customUser32.GetForegroundWindow();
        char[] windowText = new char[512];
        user32.GetWindowText(hwnd, windowText, 512);
        String windowTitle = Native.toString(windowText);

        String before = getClipboardText();
        controlC(customUser32); // emulate Ctrl C
        Thread.sleep(100); // give it some time
        // restore what was previously in the clipboard
        setClipboardText(before);

        return windowTitle;

    }

    String getWindowTitle(Foo foo) throws Exception{
        return (foo.getWindowTitle(User32.INSTANCE, CustomUser32.INSTANCE));
    }

    String getSelectedText(Foo foo) throws Exception{
        return (foo.getSelectedText(User32.INSTANCE, CustomUser32.INSTANCE));
    }

}

it works fine when i select some text by dragging the mouse
but my problem is that when i use the mouse drag to something else (like: moving a file),it doesn't return empty String it returns the clipboard text(text that copied to the clipboard), whenever it should return an empty String because i have selected nothing at that case.

can someone suggest me another better way to monitor the selected text from the global screen, or tell me solve this problem?

[Kustaa Nyholm]

I don't see the connection to JNA here ... maybe better luck on some other mailing list related to your platform, what ever it is.

br Kusti

> (customUser32); // emulate Ctrl C
>
>
> Thread.sleep(100); // give it some time
>
>
> // restore what was previously in the clipboard
>
> setClipboardText
> (before);
>
>
>
> return windowTitle;
>
>
>
> }
>
>
>
> String getWindowTitle(Foo foo) throws Exception{
>
>
> return (foo.getWindowTitle(User32.INSTANCE, CustomUser32.INSTANCE));
>
>
> }
>
>
>
> String getSelectedText(Foo foo) throws Exception{
>
>
> return (foo.getSelectedText(User32.INSTANCE, CustomUser32.INSTANCE));
>
>
> }
>
>
>
> }
>
> it works fine when i select some text by dragging the mouse
> but my problem is that when i use the mouse drag to something else (like: moving a file),it doesn't return empty String it returns the clipboard text(text that copied to the clipboard), whenever it should return an empty String because i have selected nothing at that case.
>
> can someone suggest me another better way to monitor the selected text from the global screen, or tell me solve this problem?
>
>

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[Neil C Smith]

Well, there's a bit of JNA in there somewhere! ;-)

Obvious thought would be, what happens when you hit CTRL-C when nothing is selected? What if it's a no op? Your code seems to assume the clipboard value has changed. Maybe check if text still equals before and return an empty string in that case?

Surely there's a better way to do this?!

Best wishes,

Neil

Neil C Smith
Artist : Technologist : Adviser
http://neilcsmith.net