Re: [Gzz] fourth PEG cursors--humppake: Changing mouse cursor

[Tuomas Lukka]

This is very close to being accepted now.

On Mon, May 12, 2003 at 03:19:21PM +0300, Asko Soukka wrote:
> - How the mouse cursor should be changed?
> 
>       RESOLVED: Calling 
> ``org.nongnu.libvob.GraphicsAPI.Window.setCursor()``
>       with ID of wanted cursor as a parameter. Of course setCursor() 
> method
>         should be implemented separately for both AWT and GL.
> 
>       RE-RESOLVED: Calling 
> ``org.nongnu.libvob.GraphicsAPI.Window.setCursor()``
>       with java.awt.Cursor as parameter.
> 
>       RE-RESOLVED: Calling 
> ``org.nongnu.libvob.GraphicsAPI.Window.setCursor()``
>       with proper cursor name string as parameter.
> 
>       AWTAPI will also have setCursor() overloaded with java.awt.Cursor 
>         as parameter..


Resolutions should ALWAYS contain reasons for *why* it was decided
to do a certain way. This is ESPECIALLY important if you re-resolve 
the issue.

> - How is changing the mouse cursor implemented?
>       
>       RESOLVED: Java AWT client uses ``java.awt.Cursor``, which can
>         be passed to any ``java.awt.Component`` - like ScreenCanvas in
>         AWTScreen. GL client needs a platform specific implementation.
>         Currently we are supporting X implementation. In X Windows,
>         mouse cursor could be changed via Xlib.

Is this really an issue? Did someone have a problem with this?

> - How cursor name string is mapped to Xlib mouse cursor values?
> 
>       RE-RESOLVED: Cursor name string is passed on in
>       ``org.nongnu.libvob.impl.gl.GLScreen`` and
>         low level implementation like using Xlib is determined later
>         on. Most probably in /src/os/Os-GLX.

Again, why?


> Changes
> =======
> 
> Interfaces
> ----------
> 
> Into ``org.nongnu.libvob.GraphicsAPI.Window``::
> 
>     /** Set the mouse cursor for the window.
>      * Available cursor types  (case insensitive):
>      * "CROSSHAIR_CURSOR"  The crosshair cursor type.
>      * "DEFAULT_CURSOR" The default cursor type (gets set if no cursor is 
> defined).
>      * "E_RESIZE_CURSOR" The east-resize cursor type.
>      * "HAND_CURSOR" The hand cursor type.
>      * "MOVE_CURSOR" The move cursor type.
>      * "N_RESIZE_CURSOR" The north-resize cursor type.
>      * "NE_RESIZE_CURSOR" The north-east-resize cursor type.
>      * "NW_RESIZE_CURSOR" The north-west-resize cursor type.
>      * "S_RESIZE_CURSOR" The south-resize cursor type.
>      * "SE_RESIZE_CURSOR" The south-east-resize cursor type.
>      * "SW_RESIZE_CURSOR" The south-west-resize cursor type.
>      * "TEXT_CURSOR" The text cursor type.
>      * "W_RESIZE_CURSOR" The west-resize cursor type.
>      * "WAIT_CURSOR" The wait cursor type.
>      */

ISSUE: Do we *really* want all arguments to this method have the _CURSOR
suffix?


>     public void setCursor(String shape);
> 
> Into ``org.nongnu.libvob.impl.awt.AWTScreen``::
>  
>     /** Set the mouse cursor for the window.
>      */       

Javadoc needs more - "to an AWT Cursor object".

>     public void setCursor(Cursor cursor) {
>         canvas.setCursor(cursor);
>     }
> 
> 
> 
> Implementation
> --------------
> 
> Java
> """"
> 
> Into ``org.nongnu.libvob.impl.awt.AWTScreen``::
>  
>     public void setCursor(String cursorName) {
>         Cursor cursor = null;
>       if (cursorName == "CROSSHAIR_CURSOR")
>         cursor = new Cursor(Cursor.CROSSHAIR_CURSOR);
>       else if (cursorName == "DEFAULT_CURSOR")
>         cursor = new Cursor(Cursor.DEFAULT_CURSOR);
>       else if (cursorName == "E_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.E_RESIZE_CURSOR);
>       else if (cursorName == "HAND_CURSOR")
>         cursor = new Cursor(Cursor.HAND_CURSOR);
>       else if (cursorName == "MOVE_CURSOR")
>         cursor = new Cursor(Cursor.MOVE_CURSOR);
>       else if (cursorName == "N_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.N_RESIZE_CURSOR);
>       else if (cursorName == "NE_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.NE_RESIZE_CURSOR);
>       else if (cursorName == "NW_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.NW_RESIZE_CURSOR);
>       else if (cursorName == "S_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.S_RESIZE_CURSOR);
>       else if (cursorName == "SE_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.SE_RESIZE_CURSOR);
>       else if (cursorName == "SW_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.SW_RESIZE_CURSOR);
>       else if (cursorName == "TEXT_CURSOR")
>         cursor = new Cursor(Cursor.TEXT_CURSOR);
>       else if (cursorName == "W_RESIZE_CURSOR")
>         cursor = new Cursor(Cursor.W_RESIZE_CURSOR);
>       else if (cursorName == "WAIT_CURSOR")
>         cursor = new Cursor(Cursor.WAIT_CURSOR);
>       else throw new IllegalArgumentException("Unknown cursor: 
> "+cursorName);
>       canvas.setCursor(cursor);
>     }

Using reflection is also possible.

> Into ``org.nongnu.libvob.gl.GL.Window``::
> 
>     /** Set the mouse cursor of the window.
>      */
>     public void setCursor(String cursorName) { 
> impl_Window_setCursor(getId(), cursorName); }
> 
> Into ``org.nongnu.libvob.gl.GL``::
> 
>     static private native void impl_Window_setCursor(int id, String 
> cursorName);
> 
> Into ``org.nongnu.libvob.impl.GL.GLScreen``::
> 
>     public void setCursor(String cursorName) {
>       if (cursorName == "CROSSHAIR_CURSOR" ||
>         cursorName == "DEFAULT_CURSOR" ||
>         cursorName == "E_RESIZE_CURSOR" ||
>         cursorName == "HAND_CURSOR" ||
>         cursorName == "MOVE_CURSOR" ||
>         cursorName == "N_RESIZE_CURSOR" ||
>         cursorName == "NE_RESIZE_CURSOR" ||
>         cursorName == "NW_RESIZE_CURSOR" ||
>         cursorName == "S_RESIZE_CURSOR" ||
>         cursorName == "SE_RESIZE_CURSOR" ||
>         cursorName == "SW_RESIZE_CURSOR" ||
>         cursorName == "TEXT_CURSOR" ||
>         cursorName == "W_RESIZE_CURSOR" ||
>         cursorName == "WAIT_CURSOR")

That code won't work. Can't compare strings using ==.

>             window.setCursor(cursorName);
>       else throw new IllegalArgumentException("Unknown cursor: 
> "+cursorName);
>     }
> C

        Tuomas