emacs/java/org/gnu/emacs/EmacsWindow.java

/* Communication module for Android terminals.  -*- c-file-style: "GNU" -*-

Copyright (C) 2023 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

package org.gnu.emacs;

import java.lang.IllegalStateException;
import java.util.ArrayList;
import java.util.List;
import java.util.HashMap;

import android.content.Context;

import android.graphics.Rect;
import android.graphics.Canvas;
import android.graphics.Bitmap;
import android.graphics.Point;
import android.graphics.PixelFormat;

import android.view.View;
import android.view.ViewManager;
import android.view.ViewGroup;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.InputDevice;
import android.view.WindowManager;

import android.content.Intent;
import android.util.Log;

import android.os.Build;

/* This defines a window, which is a handle.  Windows represent a
   rectangular subset of the screen with their own contents.

   Windows either have a parent window, in which case their views are
   attached to the parent's view, or are "floating", in which case
   their views are attached to the parent activity (if any), else
   nothing.

   Views are also drawables, meaning they can accept drawing
   requests.  */

/* Help wanted.  What does not work includes `EmacsView.raise',
   `EmacsView.lower', reparenting a window onto another window.

   All three are likely undocumented restrictions within
   EmacsSurface.  */

public class EmacsWindow extends EmacsHandleObject
  implements EmacsDrawable
{
  private static final String TAG = "EmacsWindow";

  private class Coordinate
  {
    /* Integral coordinate.  */
    int x, y;

    Coordinate (int x, int y)
    {
      this.x = x;
      this.y = y;
    }
  };

  /* The view associated with the window.  */
  public EmacsView view;

  /* The geometry of the window.  */
  private Rect rect;

  /* The parent window, or null if it is the root window.  */
  public EmacsWindow parent;

  /* List of all children in stacking order.  This must be kept
     consistent!  */
  public ArrayList<EmacsWindow> children;

  /* Map between pointer identifiers and last known position.  Used to
     compute which pointer changed upon a touch event.  */
  private HashMap<Integer, Coordinate> pointerMap;

  /* The window consumer currently attached, if it exists.  */
  private EmacsWindowAttachmentManager.WindowConsumer attached;

  /* The window background scratch GC.  foreground is always the
     window background.  */
  private EmacsGC scratchGC;

  /* The button state and keyboard modifier mask at the time of the
     last button press or release event.  */
  private int lastButtonState, lastModifiers;

  /* Whether or not the window is mapped, and whether or not it is
     deiconified.  */
  private boolean isMapped, isIconified;

  /* Whether or not to ask for focus upon being mapped, and whether or
     not the window should be focusable.  */
  private boolean dontFocusOnMap, dontAcceptFocus;

  /* Whether or not the window is override-redirect.  An
     override-redirect window always has its own system window.  */
  private boolean overrideRedirect;

  /* The window manager that is the parent of this window.  NULL if
     there is no such window manager.  */
  private WindowManager windowManager;

  public
  EmacsWindow (short handle, final EmacsWindow parent, int x, int y,
	       int width, int height, boolean overrideRedirect)
  {
    super (handle);

    rect = new Rect (x, y, x + width, y + height);
    pointerMap = new HashMap<Integer, Coordinate> ();

    /* Create the view from the context's UI thread.  The window is
       unmapped, so the view is GONE.  */
    view = EmacsService.SERVICE.getEmacsView (this, View.GONE,
					      parent == null);
    this.parent = parent;
    this.overrideRedirect = overrideRedirect;

    /* Create the list of children.  */
    children = new ArrayList<EmacsWindow> ();

    if (parent != null)
      {
	parent.children.add (this);
        EmacsService.SERVICE.runOnUiThread (new Runnable () {
	    @Override
	    public void
	    run ()
	    {
	      parent.view.addView (view);
	    }
	  });
      }

    scratchGC = new EmacsGC ((short) 0);
  }

  public void
  changeWindowBackground (int pixel)
  {
    /* scratchGC is used as the argument to a FillRectangles req.  */
    scratchGC.foreground = pixel;
    scratchGC.markDirty ();
  }

  public Rect
  getGeometry ()
  {
    synchronized (this)
      {
	/* Huh, this is it.  */
	return rect;
      }
  }

  @Override
  public void
  destroyHandle () throws IllegalStateException
  {
    if (parent != null)
      parent.children.remove (this);

    EmacsActivity.invalidateFocus ();

    if (!children.isEmpty ())
      throw new IllegalStateException ("Trying to destroy window with "
				       + "children!");

    /* Remove the view from its parent and make it invisible.  */
    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	public void
	run ()
	{
	  ViewManager parent;
	  EmacsWindowAttachmentManager manager;

	  if (EmacsActivity.focusedWindow == EmacsWindow.this)
	    EmacsActivity.focusedWindow = null;

	  manager = EmacsWindowAttachmentManager.MANAGER;
	  view.setVisibility (View.GONE);

	  /* If the window manager is set, use that instead.  */
	  if (windowManager != null)
	    parent = windowManager;
	  else
	    parent = (ViewManager) view.getParent ();
	  windowManager = null;

	  if (parent != null)
	    parent.removeView (view);

	  manager.detachWindow (EmacsWindow.this);
	}
      });

    super.destroyHandle ();
  }

  public void
  setConsumer (EmacsWindowAttachmentManager.WindowConsumer consumer)
  {
    attached = consumer;
  }

  public EmacsWindowAttachmentManager.WindowConsumer
  getAttachedConsumer ()
  {
    return attached;
  }

  public void
  viewLayout (int left, int top, int right, int bottom)
  {
    int rectWidth, rectHeight;

    synchronized (this)
      {
	rect.left = left;
	rect.top = top;
	rect.right = right;
	rect.bottom = bottom;
      }

    rectWidth = right - left;
    rectHeight = bottom - top;

    EmacsNative.sendConfigureNotify (this.handle,
				     System.currentTimeMillis (),
				     left, top, rectWidth,
				     rectHeight);
  }

  public void
  requestViewLayout ()
  {
    /* This is necessary because otherwise subsequent drawing on the
       Emacs thread may be lost.  */
    view.explicitlyDirtyBitmap (rect);

    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	@Override
	public void
	run ()
	{
	  if (overrideRedirect)
	    /* Set the layout parameters again.  */
	    view.setLayoutParams (getWindowLayoutParams ());

	  view.mustReportLayout = true;
	  view.requestLayout ();
	}
      });
  }

  public void
  resizeWindow (int width, int height)
  {
    synchronized (this)
      {
	rect.right = rect.left + width;
	rect.bottom = rect.top + height;

	requestViewLayout ();
      }
  }

  public void
  moveWindow (int x, int y)
  {
    int width, height;

    synchronized (this)
      {
	width = rect.width ();
	height = rect.height ();

	rect.left = x;
	rect.top = y;
	rect.right = x + width;
	rect.bottom = y + height;

	requestViewLayout ();
      }
  }

  private WindowManager.LayoutParams
  getWindowLayoutParams ()
  {
    WindowManager.LayoutParams params;
    int flags, type;
    Rect rect;

    flags = 0;
    rect = getGeometry ();
    flags |= WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
    flags |= WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
    type = WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;

    params
      = new WindowManager.LayoutParams (rect.width (), rect.height (),
					rect.left, rect.top,
					type, flags,
					PixelFormat.RGBA_8888);
    params.gravity = Gravity.TOP | Gravity.LEFT;
    return params;
  }

  private Context
  findSuitableActivityContext ()
  {
    /* Find a recently focused activity.  */
    if (!EmacsActivity.focusedActivities.isEmpty ())
      return EmacsActivity.focusedActivities.get (0);

    /* Return the service context, which probably won't work.  */
    return EmacsService.SERVICE;
  }

  public void
  mapWindow ()
  {
    if (isMapped)
      return;

    isMapped = true;

    if (parent == null)
      {
        EmacsService.SERVICE.runOnUiThread (new Runnable () {
	    @Override
	    public void
	    run ()
	    {
	      EmacsWindowAttachmentManager manager;
	      WindowManager windowManager;
	      Context ctx;
	      Object tem;
	      WindowManager.LayoutParams params;

	      /* Make the view visible, first of all.  */
	      view.setVisibility (View.VISIBLE);

	      if (!overrideRedirect)
		{
		  manager = EmacsWindowAttachmentManager.MANAGER;

		  /* If parent is the root window, notice that there are new
		     children available for interested activites to pick
		     up.  */
		  manager.registerWindow (EmacsWindow.this);

		  if (!getDontFocusOnMap ())
		    /* Eventually this should check no-focus-on-map.  */
		    view.requestFocus ();
		}
	      else
		{
		  /* But if the window is an override-redirect window,
		     then:

		     - Find an activity that is currently active.

		     - Map the window as a panel on top of that
                       activity using the system window manager.  */

		  ctx = findSuitableActivityContext ();
		  tem = ctx.getSystemService (Context.WINDOW_SERVICE);
		  windowManager = (WindowManager) tem;

		  /* Calculate layout parameters.  */
		  params = getWindowLayoutParams ();
		  view.setLayoutParams (params);

		  /* Attach the view.  */
		  try
		    {
		      windowManager.addView (view, params);

		      /* Record the window manager being used in the
			 EmacsWindow object.  */
		      EmacsWindow.this.windowManager = windowManager;
		    }
		  catch (Exception e)
		    {
		      Log.w (TAG,
			     "failed to attach override-redirect window, " + e);
		    }
		}
	    }
	  });
      }
    else
      {
	/* Do the same thing as above, but don't register this
	   window.  */
        EmacsService.SERVICE.runOnUiThread (new Runnable () {
	    @Override
	    public void
	    run ()
	    {
	      view.setVisibility (View.VISIBLE);

	      if (!getDontFocusOnMap ())
	      /* Eventually this should check no-focus-on-map.  */
		view.requestFocus ();
	    }
	  });
      }
  }

  public void
  unmapWindow ()
  {
    if (!isMapped)
      return;

    isMapped = false;

    view.post (new Runnable () {
	@Override
	public void
	run ()
	{
	  EmacsWindowAttachmentManager manager;

	  manager = EmacsWindowAttachmentManager.MANAGER;

	  view.setVisibility (View.GONE);

	  /* Detach the view from the window manager if possible.  */
	  if (windowManager != null)
	    windowManager.removeView (view);
	  windowManager = null;

	  /* Now that the window is unmapped, unregister it as
	     well.  */
	  manager.detachWindow (EmacsWindow.this);
	}
      });
  }

  @Override
  public Canvas
  lockCanvas ()
  {
    return view.getCanvas ();
  }

  @Override
  public void
  damageRect (Rect damageRect)
  {
    view.damageRect (damageRect);
  }

  public void
  swapBuffers ()
  {
    view.swapBuffers ();
  }

  public void
  clearWindow ()
  {
    synchronized (this)
      {
	EmacsService.SERVICE.fillRectangle (this, scratchGC,
					    0, 0, rect.width (),
					    rect.height ());
      }
  }

  public void
  clearArea (int x, int y, int width, int height)
  {
    EmacsService.SERVICE.fillRectangle (this, scratchGC,
					x, y, width, height);
  }

  @Override
  public Bitmap
  getBitmap ()
  {
    return view.getBitmap ();
  }

  public void
  onKeyDown (int keyCode, KeyEvent event)
  {
    int state;

    state = event.getModifiers ();
    state &= ~(KeyEvent.META_ALT_MASK | KeyEvent.META_CTRL_MASK);

    EmacsNative.sendKeyPress (this.handle,
			      event.getEventTime (),
			      event.getModifiers (),
			      keyCode,
			      /* Ignore meta-state understood by Emacs
				 for now, or Ctrl+C will not be
				 recognized as an ASCII key press
				 event.  */
			      event.getUnicodeChar (state));
    lastModifiers = event.getModifiers ();
  }

  public void
  onKeyUp (int keyCode, KeyEvent event)
  {
    int state;

    state = event.getModifiers ();
    state &= ~(KeyEvent.META_ALT_MASK | KeyEvent.META_CTRL_MASK);

    EmacsNative.sendKeyRelease (this.handle,
				event.getEventTime (),
				event.getModifiers (),
				keyCode,
				event.getUnicodeChar (state));
    lastModifiers = event.getModifiers ();
  }

  public void
  onFocusChanged (boolean gainFocus)
  {
    EmacsActivity.invalidateFocus ();
  }

  public void
  onActivityDetached ()
  {
    /* Destroy the associated frame when the activity is detached.  */
    EmacsNative.sendWindowAction (this.handle, 0);
  }

  /* Look through the button state to determine what button EVENT was
     generated from.  DOWN is true if EVENT is a button press event,
     false otherwise.  Value is the X number of the button.  */

  private int
  whatButtonWasIt (MotionEvent event, boolean down)
  {
    int eventState, notIn;

    if (Build.VERSION.SDK_INT
	< Build.VERSION_CODES.ICE_CREAM_SANDWICH)
      /* Earlier versions of Android only support one mouse
	 button.  */
      return 1;

    eventState = event.getButtonState ();
    notIn = (down ? eventState & ~lastButtonState
	     : lastButtonState & ~eventState);

    if ((notIn & MotionEvent.BUTTON_PRIMARY) != 0)
      return 1;

    if ((notIn & MotionEvent.BUTTON_SECONDARY) != 0)
      return 3;

    if ((notIn & MotionEvent.BUTTON_TERTIARY) != 0)
      return 2;

    /* Not a real value.  */
    return 4;
  }

  /* Return the ID of the pointer which changed in EVENT.  Value is -1
     if it could not be determined, else the pointer that changed, or
     -2 if -1 would have been returned, but there is also a pointer
     that is a mouse.  */

  private int
  figureChange (MotionEvent event)
  {
    int pointerID, i, truncatedX, truncatedY, pointerIndex;
    Coordinate coordinate;
    boolean mouseFlag;

    /* pointerID is always initialized but the Java compiler is too
       dumb to know that.  */
    pointerID = -1;
    mouseFlag = false;

    switch (event.getActionMasked ())
      {
      case MotionEvent.ACTION_DOWN:
	/* Primary pointer pressed with index 0.  */

	/* Detect mice.  If this is a mouse event, give it to
	   onSomeKindOfMotionEvent.  */
	if ((Build.VERSION.SDK_INT
	     >= Build.VERSION_CODES.ICE_CREAM_SANDWICH)
	    && event.getToolType (0) == MotionEvent.TOOL_TYPE_MOUSE)
	  return -2;

	pointerID = event.getPointerId (0);
	pointerMap.put (pointerID,
			new Coordinate ((int) event.getX (0),
					(int) event.getY (0)));
	break;

      case MotionEvent.ACTION_UP:
	/* Primary pointer released with index 0.  */
	pointerID = event.getPointerId (0);
	pointerMap.remove (pointerID);
	break;

      case MotionEvent.ACTION_POINTER_DOWN:
	/* New pointer.  Find the pointer ID from the index and place
	   it in the map.  */
	pointerIndex = event.getActionIndex ();
	pointerID = event.getPointerId (pointerIndex);
	pointerMap.put (pointerID,
			new Coordinate ((int) event.getX (pointerID),
					(int) event.getY (pointerID)));
	break;

      case MotionEvent.ACTION_POINTER_UP:
	/* Pointer removed.  Remove it from the map.  */
	pointerIndex = event.getActionIndex ();
	pointerID = event.getPointerId (pointerIndex);
	pointerMap.remove (pointerID);
	break;

      default:

	/* Loop through each pointer in the event.  */
	for (i = 0; i < event.getPointerCount (); ++i)
	  {
	    pointerID = event.getPointerId (i);

	    /* Look up that pointer in the map.  */
	    coordinate = pointerMap.get (pointerID);

	    if (coordinate != null)
	      {
		/* See if coordinates have changed.  */
		truncatedX = (int) event.getX (i);
		truncatedY = (int) event.getY (i);

		if (truncatedX != coordinate.x
		    || truncatedY != coordinate.y)
		  {
		    /* The pointer changed.  Update the coordinate and
		       break out of the loop.  */
		    coordinate.x = truncatedX;
		    coordinate.y = truncatedY;

		    break;
		  }
	      }

	    /* See if this is a mouse.  If so, set the mouseFlag.  */
	    if ((Build.VERSION.SDK_INT
		 >= Build.VERSION_CODES.ICE_CREAM_SANDWICH)
		&& event.getToolType (i) == MotionEvent.TOOL_TYPE_MOUSE)
	      mouseFlag = true;
	  }

	/* Set the pointer ID to -1 if the loop failed to find any
	   changed pointer.  If a mouse pointer was found, set it to
	   -2.  */
	if (i == event.getPointerCount ())
	  pointerID = (mouseFlag ? -2 : -1);
      }

    /* Return the pointer ID.  */
    return pointerID;
  }

  public boolean
  onTouchEvent (MotionEvent event)
  {
    int pointerID, index;

    /* Extract the ``touch ID'' (or in Android, the ``pointer
       ID''.) */
    pointerID = figureChange (event);

    if (pointerID < 0)
      {
	/* If this is a mouse event, give it to
	   onSomeKindOfMotionEvent.  */
	if (pointerID == -2)
	  return onSomeKindOfMotionEvent (event);

	return false;
      }

    /* Find the pointer index corresponding to the event.  */
    index = event.findPointerIndex (pointerID);

    switch (event.getActionMasked ())
      {
      case MotionEvent.ACTION_DOWN:
      case MotionEvent.ACTION_POINTER_DOWN:
	/* Touch down event.  */
	EmacsNative.sendTouchDown (this.handle, (int) event.getX (index),
				   (int) event.getY (index),
				   event.getEventTime (), pointerID);
	return true;

      case MotionEvent.ACTION_UP:
      case MotionEvent.ACTION_POINTER_UP:
	/* Touch up event.  */
	EmacsNative.sendTouchUp (this.handle, (int) event.getX (index),
				 (int) event.getY (index),
				 event.getEventTime (), pointerID);
	return true;

      case MotionEvent.ACTION_MOVE:
	/* Pointer motion event.  */
	EmacsNative.sendTouchMove (this.handle, (int) event.getX (index),
				   (int) event.getY (index),
				   event.getEventTime (), pointerID);
	return true;
      }

    return false;
  }

  public boolean
  onSomeKindOfMotionEvent (MotionEvent event)
  {
    if (!event.isFromSource (InputDevice.SOURCE_CLASS_POINTER))
      return false;

    switch (event.getAction ())
      {
      case MotionEvent.ACTION_HOVER_ENTER:
	EmacsNative.sendEnterNotify (this.handle, (int) event.getX (),
				     (int) event.getY (),
				     event.getEventTime ());
	return true;

      case MotionEvent.ACTION_MOVE:
      case MotionEvent.ACTION_HOVER_MOVE:
	EmacsNative.sendMotionNotify (this.handle, (int) event.getX (),
				      (int) event.getY (),
				      event.getEventTime ());
	return true;

      case MotionEvent.ACTION_HOVER_EXIT:
	EmacsNative.sendLeaveNotify (this.handle, (int) event.getX (),
				     (int) event.getY (),
				     event.getEventTime ());
	return true;

      case MotionEvent.ACTION_BUTTON_PRESS:
	/* Find the button which was pressed.  */
	EmacsNative.sendButtonPress (this.handle, (int) event.getX (),
				     (int) event.getY (),
				     event.getEventTime (),
				     lastModifiers,
				     whatButtonWasIt (event, true));

	if (Build.VERSION.SDK_INT
	    < Build.VERSION_CODES.ICE_CREAM_SANDWICH)
	  return true;

	lastButtonState = event.getButtonState ();
	return true;

      case MotionEvent.ACTION_BUTTON_RELEASE:
	/* Find the button which was released.  */
	EmacsNative.sendButtonRelease (this.handle, (int) event.getX (),
				       (int) event.getY (),
				       event.getEventTime (),
				       lastModifiers,
				       whatButtonWasIt (event, false));

	if (Build.VERSION.SDK_INT
	    < Build.VERSION_CODES.ICE_CREAM_SANDWICH)
	  return true;

	lastButtonState = event.getButtonState ();
	return true;

      case MotionEvent.ACTION_DOWN:
      case MotionEvent.ACTION_UP:
	/* Emacs must return true even though touch events are not
	   handled here, because the value of this function is used by
	   the system to decide whether or not Emacs gets ACTION_MOVE
	   events.  */
	return true;

      case MotionEvent.ACTION_SCROLL:
	/* Send a scroll event with the specified deltas.  */
	EmacsNative.sendWheel (this.handle, (int) event.getX (),
			       (int) event.getY (),
			       event.getEventTime (),
			       lastModifiers,
			       event.getAxisValue (MotionEvent.AXIS_HSCROLL),
			       event.getAxisValue (MotionEvent.AXIS_VSCROLL));
	return true;
      }

    return false;
  }

  public void
  reparentTo (final EmacsWindow otherWindow, int x, int y)
  {
    int width, height;

    /* Reparent this window to the other window.  */

    if (parent != null)
      parent.children.remove (this);

    if (otherWindow != null)
      otherWindow.children.add (this);

    parent = otherWindow;

    /* Move this window to the new location.  */
    synchronized (this)
      {
	width = rect.width ();
	height = rect.height ();
	rect.left = x;
	rect.top = y;
	rect.right = x + width;
	rect.bottom = y + height;
      }

    /* Now do the work necessary on the UI thread to reparent the
       window.  */
    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	@Override
	public void
	run ()
	{
	  EmacsWindowAttachmentManager manager;
	  ViewManager parent;

	  /* First, detach this window if necessary.  */
	  manager = EmacsWindowAttachmentManager.MANAGER;
	  manager.detachWindow (EmacsWindow.this);

	  /* Also unparent this view.  */

	  /* If the window manager is set, use that instead.  */
	  if (windowManager != null)
	    parent = windowManager;
	  else
	    parent = (ViewManager) view.getParent ();
	  windowManager = null;

	  if (parent != null)
	    parent.removeView (view);

	  /* Next, either add this window as a child of the new
	     parent's view, or make it available again.  */
	  if (otherWindow != null)
	    otherWindow.view.addView (view);
	  else if (EmacsWindow.this.isMapped)
	    manager.registerWindow (EmacsWindow.this);

	  /* Request relayout.  */
	  view.requestLayout ();
	}
      });
  }

  public void
  makeInputFocus (long time)
  {
    /* TIME is currently ignored.  Request the input focus now.  */

    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	@Override
	public void
	run ()
	{
	  view.requestFocus ();
	}
      });
  }

  public void
  raise ()
  {
    /* This does nothing here.  */
    if (parent == null)
      return;

    /* Remove and add this view again.  */
    parent.children.remove (this);
    parent.children.add (this);

    /* Request a relayout.  */
    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	@Override
	public void
	run ()
	{
	  view.raise ();
	}
      });
  }

  public void
  lower ()
  {
    /* This does nothing here.  */
    if (parent == null)
      return;

    /* Remove and add this view again.  */
    parent.children.remove (this);
    parent.children.add (this);

    /* Request a relayout.  */
    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	@Override
	public void
	run ()
	{
	  view.lower ();
	}
      });
  }

  public int[]
  getWindowGeometry ()
  {
    int[] array;
    Rect rect;

    array = new int[4];
    rect = getGeometry ();

    array[0] = rect.left;
    array[1] = rect.top;
    array[2] = rect.width ();
    array[3] = rect.height ();

    return array;
  }

  public void
  noticeIconified ()
  {
    isIconified = true;
    EmacsNative.sendIconified (this.handle);
  }

  public void
  noticeDeiconified ()
  {
    isIconified = false;
    EmacsNative.sendDeiconified (this.handle);
  }

  public synchronized void
  setDontAcceptFocus (final boolean dontAcceptFocus)
  {
    this.dontAcceptFocus = dontAcceptFocus;

    /* Update the view's focus state.  */
    EmacsService.SERVICE.runOnUiThread (new Runnable () {
	@Override
	public void
	run ()
	{
	  view.setFocusable (!dontAcceptFocus);
	  view.setFocusableInTouchMode (!dontAcceptFocus);
	}
      });
  }

  public synchronized void
  setDontFocusOnMap (final boolean dontFocusOnMap)
  {
    this.dontFocusOnMap = dontFocusOnMap;
  }

  public synchronized boolean
  getDontFocusOnMap ()
  {
    return dontFocusOnMap;
  }

  public int[]
  translateCoordinates (int x, int y)
  {
    int[] array;

    /* This is supposed to translate coordinates to the root
       window.  */
    array = new int[2];
    EmacsService.SERVICE.getLocationOnScreen (view, array);

    /* Now, the coordinates of the view should be in array.  Offset X
       and Y by them.  */
    array[0] += x;
    array[1] += y;

    /* Return the resulting coordinates.  */
    return array;
  }
};