Issues

• Do we want to change mouse cursor?

  RESOLVED: Yes, we do. Of course, different effective areas on GUI should be noticeable also without changing mouse cursor on top of them, but different mouse cursors would work as additional visual glues - except for the effective ares, also for the overall application state.

• 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. This will simplify the interface and make it consistent with java.awt.Component.setCursor().

  RE-RESOLVED: Calling org.nongnu.libvob.GraphicsAPI.Window.setCursor() with proper cursor name string as parameter. This is to avoid unwanted initializing of AWT, when using GL.

  AWTAPI can also have setCursor() overloaded with java.awt.Cursor as parameter. This allows using directly java.awt.Cursor on AWT.

• What is the available set of mouse cursors?

  RESOLVED: The set of available mouse cursors is the intersection of Xlib and AWT mouse cursors sets:

  • http://java.sun.com/products/jdk/1.2/docs/api/java/awt/Cursor.html
  • http://tronche.com/gui/x/xlib/appendix/b/

  RE-RESOLVED: To be more specific, all Java AWT cursors except custom cursor are available.

  RE-RESOLVED: A stable sub set of available cursor should be defined in Graphics API. At start, it will be the same as Java AWT cursors except the custom cursor. AWT and GL cursor APIs can then be extended (also separately).

  Names of the default cursors are similar to ones in java.awt.Cursor without the suffix "_CURSOR". In awt.Cursor there's a reason to have the suffix: they are data members of the class and it makes sense to separate the namespace. Here, that doesn't make sense.

• Should we use our own custom cursors?

  RESOLVED: Not yet. Probably we would like to use also our own custom cursors in the future, but at first it is more relevant to get at least changing of default system cursors work.

  NOTE: In Java, Toolkit.createCustomCursor is available since JDK 1.2. How custom cursor could be used efficiently in GL?

  RE-RESOLVED: Since ustom cursors should be also possible outside the AWT, using custom cursor is allowed. Althought, left yet unimplemented in GL.

  RE-RESOLVED: General GraphicsAPI won't contain custom cursor choice, but custom cursor can be added into GL and AWT APIs later on. If some cursor is implemented to them both, it can be included into general GraphicsAPI.

• How java.awt.Cursor is mapped to Xlib mouse cursor values?

  RESOLVED: Mapping is done in setCursor() method in org.nongnu.libvob.impl.gl.GLScreen using switch structure.

  RE-RESOLVED: String value corresponding to cursor is passed to on in org.nongnu.libvob.impl.gl.GLScreen and low level implementation like usin Xlib is determined later on. At first in /src/os/Os-GLX.

  RE-RESOLVED: Irrelevant. Sending string values independent of low level implementation.

• What are the mouse cursor IDs?

  RESOLVED: IDs are our own constants mapped to integer values that correspond the mouse cursors in current environment. Integers for specific mouse cursors are different in AWT and Xlib and that's why we need our own mapping for them.

  RE-RESOLVED: Irrelevant. No more IDs. IDs were originally values of different mouse cursor constants of Xlib, but they are not used anymore.

• Where are the mouse cursor ID mappings located?

  RESOLVED: Mouse cursor constants are described with AWT values as default in org.nongnu.libvob.GraphicsAPI. For GL implementation those mappings must be overwritten into org.nongnu.libvob.impl.gl.GLAPI.

  RE-RESOLVED: Irrelevant. No more IDs.

• Since it's possible to call setCursor() with pure integer values, is it allowed to use AWT or Xlib specific cursors?

  RESOLVED: Yes, but with care. If the application is runnable under both AWT and GL, there should be checking for proper GraphicsAPI..

  RESOLVED: Irrelevant. No more IDs.

Changes

/** Set the mouse cursor for the window.
 * Available cursor types. These are similar to ones
 * in java.awt.Cursor, tough the "_CURSOR" suffix
 * is dropped.
 *
 * "CROSSHAIR"  The crosshair cursor type.
 * "DEFAULT" The default cursor type (gets set if no cursor is defined).
 * "E_RESIZE" The east-resize cursor type.
 * "HAND" The hand cursor type.
 * "MOVE" The move cursor type.
 * "N_RESIZE" The north-resize cursor type.
 * "NE_RESIZE" The north-east-resize cursor type.
 * "NW_RESIZE" The north-west-resize cursor type.
 * "S_RESIZE" The south-resize cursor type.
 * "SE_RESIZE" The south-east-resize cursor type.
 * "SW_RESIZE" The south-west-resize cursor type.
 * "TEXT" The text cursor type.
 * "W_RESIZE" The west-resize cursor type.
 * "WAIT" The wait cursor type.
 */
public void setCursor(String name);

/** Set the mouse cursor for the window.
 */ 
public void setCursor(Cursor cursor) {
    canvas.setCursor(cursor);
}

public void setCursor(String name) {
    try {
        Cursor cursor = new Cursor(Cursor.class.getField(name.toUpperCase()+"_CURSOR").getInt(null));
        canvas.setCursor(cursor);
    } catch (Exception e) {
        throw new IllegalArgumentException("Unknown cursor: "+name);
    }
}

/** Set the mouse cursor of the window.
 */
public void setCursor(String name) { impl_Window_setCursor(getId(), name); }

static private native void impl_Window_setCursor(int id, String name);

public void setCursor(String name) {
  name = name.toUpperCase();
  if (name.equals("CROSSHAIR") ||
      name.equals("DEFAULT") ||
      name.equals("E_RESIZE") ||
      name.equals("HAND") ||
      name.equals("MOVE") ||
      name.equals("N_RESIZE") ||
      name.equals("NE_RESIZE") ||
      name.equals("NW_RESIZE") ||
      name.equals("S_RESIZE") ||
      name.equals("SE_RESIZE") ||
      name.equals("SW_RESIZE") ||
      name.equals("TEXT") ||
      name.equals("W_RESIZE") ||
      name.equals("WAIT"))
        window.setCursor(name);
  else throw new IllegalArgumentException("Unknown cursor: "+name);
}

virtual void setCursor(const std::string name) = 0;

jf(void, impl_1Window_1setCursor)
(JNIEnv *env, jclass, jint id, jstring name) {
      Os::Window *w = (Os::Window *)windows.get(id);
      DBG(dbg) << "Set window "<<id<<" Cursor name "<<name<<" at "<<(int)w<<"\n";
      std::string name_str = jstr2stdstr(env, name);
      w->setCursor(name_str);
}

// For setCursor()
#include <X11/Xlib.h>
#include <X11/cursorfont.h>
//

virtual void setCursor(const std::string name) {
    Cursor cursor = 0;
    if (name == "CROSSHAIR")
      cursor = XCreateFontCursor(ws->dpy, XC_crosshair);
    else if (name == "DEFAULT")
      cursor = XCreateFontCursor(ws->dpy, XC_left_ptr);
    else if (name == "E_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_right_side);
    else if (name == "HAND")
      cursor = XCreateFontCursor(ws->dpy, XC_hand2);
    else if (name == "MOVE")
      cursor = XCreateFontCursor(ws->dpy, XC_fleur);
    else if (name == "N_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_top_side);
    else if (name == "NE_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_top_right_corner);
    else if (name == "NW_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_top_left_corner);
    else if (name == "S_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_bottom_side);
    else if (name == "SE_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_bottom_right_corner);
    else if (name == "SW_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_bottom_left_corner);
    else if (name == "TEXT")
      cursor = XCreateFontCursor(ws->dpy, XC_xterm);
    else if (name == "W_RESIZE")
      cursor = XCreateFontCursor(ws->dpy, XC_left_side);
    else if (name == "WAIT")
      cursor = XCreateFontCursor(ws->dpy, XC_watch);
    if (cursor != 0) XDefineCursor(ws->dpy, xw, cursor);
}