Update Android port

* .gitignore: Update with new files.  Do not ignore std*.in.h.
* INSTALL.android: Explain how to build Emacs with external
dependencies.

* Makefile.in (xcompile, cross): Rename to `cross'.
(clean_dirs): Clean cross, not xcompile.

* README: Document new directories.

* build-aux/ndk-build-helper-1.mk (build_kind, NDK_SO_NAMES):
* build-aux/ndk-build-helper-2.mk (build_kind, NDK_SO_NAMES):
* build-aux/ndk-build-helper-3.mk (build_kind):
* build-aux/ndk-build-helper-4.mk:
* build-aux/ndk-build-helper.mk (NDK_BUILD_DIR, my-dir):
* build-aux/ndk-module-extract.awk: New files.
* configure.ac: Set up libgif, libwebp, and libpng for
ndk-build.
* cross/ndk-build/Makefile.in (srcdir, NDK_BUILD_ANDROID_MK):
* cross/ndk-build/ndk-build-executable.mk:
* cross/ndk-build/ndk-build-shared-library.mk (eq, objname):
* cross/ndk-build/ndk-build-static-library.mk (eq, objname):
* cross/ndk-build/ndk-build.in (NDK_BUILD_MODULES):
* cross/ndk-build/ndk-build.mk.in (NDK_BUILD_MODULES)
(NDK_BUILD_SHARED):
* cross/ndk-build/ndk-clear-vars.mk:
* cross/ndk-build/ndk-prebuilt-shared-library.mk:
* cross/ndk-build/ndk-prebuilt-static-library.mk: New files.
* doc/emacs/android.texi (Android, Android Environment):
Document clipboard support on Android.
* doc/emacs/emacs.texi (Top): Update menus.
* etc/MACHINES: Document Android.
* java/AndroidManifest.xml.in: Respect new
`--with-android-debug' option.
* java/Makefile.in (CROSS_BINS, CROSS_LIBS): Adjust for rename.
Include ndk-build.mk.:(emacs.apk-in): Depend on shared
libraries.  Then, package shared libraries.
* java/org/gnu/emacs/EmacsClipboard.java (EmacsClipboard): New
class.
* java/org/gnu/emacs/EmacsFontDriver.java: Update comment to say
this is unused.
* java/org/gnu/emacs/EmacsNative.java (EmacsNative): New
function `sendExpose'.
* java/org/gnu/emacs/EmacsSdk11Clipboard.java
(EmacsSdk11Clipboard):
* java/org/gnu/emacs/EmacsSdk8Clipboard.java
(EmacsSdk8Clipboard): New classes.
* java/org/gnu/emacs/EmacsView.java (EmacsView, handleDirtyBitmap)
(onDetachedFromWindow): When window is reattached, expose the
frame.

* lib/Makefile.in (VPATH):
(ALL_CFLAGS): Adjust for rename.

* lisp/term/android-win.el (android-clipboard-exists-p)
(android-get-clipboard, android-set-clipboard)
(android-clipboard-owner-p, android-primary-selection)
(android-get-clipboard-1, android-get-primary)
(android-selection-bounds, android-encode-select-string)
(gui-backend-get-selection, gui-backend-selection-exists-p)
(gui-backend-selection-owner-p, gui-backend-set-selection): New
functions.

* m4/ndk-build.m4: New file.
* src/Makefile.in (GIF_CFLAGS, ANDROID_LDFLAGS): New variables.
(EMACS_CFLAGS): Add GIF_CFLAGS.  Include
ndk-build.mk.
(libemacs.so): Depend on and link with required
libraries.

* src/android.c (android_check_compressed_file): New function.
(android_open): Work around Android platform bug.
(sendExpose): New function.
(android_readdir): Set d_type if this is a directory.

* src/androidgui.h (enum android_event_type)
(struct android_expose_event, union android_event): Add expose
events.

* src/androidselect.c (struct android_emacs_clipboard)
(android_init_emacs_clipboard, Fandroid_clipboard_owner_p)
(Fandroid_set_clipboard, Fandroid_get_clipboard)
(Fandroid_clipboard_exists_p, init_androidselect)
(syms_of_androidselect): New file.

* src/androidterm.c (handle_one_android_event): Handle
exposures.
* src/androidterm.h: Update prototypes.
* src/emacs.c (android_emacs_init): Initialize androidselect.

java/org/gnu/emacs/EmacsClipboard.java

@@ -0,0 +1,44 @@
+/* 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 android.os.Build;
+
+/* This class provides helper code for accessing the clipboard,
+   abstracting between the different interfaces on API 8 and 11.  */
+
+public abstract class EmacsClipboard
+{
+  public abstract void setClipboard (byte[] bytes);
+  public abstract int ownsClipboard ();
+  public abstract boolean clipboardExists ();
+  public abstract byte[] getClipboard ();
+
+  /* Create the correct kind of clipboard for this system.  */
+
+  public static EmacsClipboard
+  makeClipboard ()
+  {
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
+      return new EmacsSdk11Clipboard ();
+    else
+      return new EmacsSdk8Clipboard ();
+  }
+};

java/org/gnu/emacs/EmacsFontDriver.java

@@ -23,6 +23,9 @@ import java.util.List;
 
 import android.os.Build;
 
+/* This code is mostly unused.  See sfntfont-android.c for the code
+   that is actually used.  */
+
 public abstract class EmacsFontDriver
 {
   /* Font weights.  */

java/org/gnu/emacs/EmacsNative.java

@@ -132,6 +132,10 @@ public class EmacsNative
   /* Send an ANDROID_CONTEXT_MENU event.  */
   public static native long sendContextMenu (short window, int menuEventID);
 
+  /* Send an ANDROID_EXPOSE event.  */
+  public static native long sendExpose (short window, int x, int y,
+					int width, int height);
+
   static
   {
     System.loadLibrary ("emacs");

java/org/gnu/emacs/EmacsSdk11Clipboard.java

@@ -0,0 +1,156 @@
+/* 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 android.content.ClipboardManager;
+import android.content.Context;
+import android.content.ClipData;
+
+import android.util.Log;
+
+import java.io.UnsupportedEncodingException;
+
+/* This class implements EmacsClipboard for Android 3.0 and later
+   systems.  */
+
+public class EmacsSdk11Clipboard extends EmacsClipboard
+  implements ClipboardManager.OnPrimaryClipChangedListener
+{
+  private static final String TAG = "EmacsSdk11Clipboard";
+  private ClipboardManager manager;
+  private boolean ownsClipboard;
+  private int clipboardChangedCount;
+  private int monitoredClipboardChangedCount;
+
+  public
+  EmacsSdk11Clipboard ()
+  {
+    String what;
+    Context context;
+
+    what = Context.CLIPBOARD_SERVICE;
+    context = EmacsService.SERVICE;
+    manager
+      = (ClipboardManager) context.getSystemService (what);
+    manager.addPrimaryClipChangedListener (this);
+  }
+
+  @Override
+  public synchronized void
+  onPrimaryClipChanged ()
+  {
+    Log.d (TAG, ("onPrimaryClipChanged: "
+		 + monitoredClipboardChangedCount
+		 + " " + clipboardChangedCount));
+
+    /* Increment monitoredClipboardChangeCount.  If it is now greater
+       than clipboardChangedCount, then Emacs no longer owns the
+       clipboard.  */
+    monitoredClipboardChangedCount++;
+
+    if (monitoredClipboardChangedCount > clipboardChangedCount)
+      {
+	ownsClipboard = false;
+
+	/* Reset both values back to 0.  */
+	monitoredClipboardChangedCount = 0;
+	clipboardChangedCount = 0;
+      }
+  }
+
+  /* Set the clipboard text to CLIPBOARD, a string in UTF-8
+     encoding.  */
+
+  @Override
+  public synchronized void
+  setClipboard (byte[] bytes)
+  {
+    ClipData data;
+    String string;
+
+    try
+      {
+	string = new String (bytes, "UTF-8");
+	data = ClipData.newPlainText ("Emacs", string);
+	manager.setPrimaryClip (data);
+	ownsClipboard = true;
+
+	/* onPrimaryClipChanged will be called again.  Use this
+	   variable to keep track of how many times the clipboard has
+	   been changed.  */
+	++clipboardChangedCount;
+      }
+    catch (UnsupportedEncodingException exception)
+      {
+	Log.w (TAG, "setClipboard: " + exception);
+      }
+  }
+
+  /* Return whether or not Emacs owns the clipboard.  Value is 1 if
+     Emacs does, 0 if Emacs does not, and -1 if that information is
+     unavailable.  */
+
+  @Override
+  public synchronized int
+  ownsClipboard ()
+  {
+    return ownsClipboard ? 1 : 0;
+  }
+
+  /* Return whether or not clipboard content currently exists.  */
+
+  @Override
+  public boolean
+  clipboardExists ()
+  {
+    return manager.hasPrimaryClip ();
+  }
+
+  /* Return the current content of the clipboard, as plain text, or
+     NULL if no content is available.  */
+
+  @Override
+  public byte[]
+  getClipboard ()
+  {
+    ClipData clip;
+    CharSequence text;
+    Context context;
+
+    clip = manager.getPrimaryClip ();
+
+    if (clip == null || clip.getItemCount () < 1)
+      return null;
+
+    context = EmacsService.SERVICE;
+
+    try
+      {
+	text = clip.getItemAt (0).coerceToText (context);
+	return text.toString ().getBytes ("UTF-8");
+      }
+    catch (UnsupportedEncodingException exception)
+      {
+	Log.w (TAG, "getClipboard: " + exception);
+      }
+
+    return null;
+  }
+};

java/org/gnu/emacs/EmacsSdk8Clipboard.java

@@ -0,0 +1,116 @@
+/* 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;
+
+/* Importing the entire package avoids the deprecation warning.  */
+import android.text.*;
+
+import android.content.Context;
+import android.util.Log;
+
+import java.io.UnsupportedEncodingException;
+
+/* This class implements EmacsClipboard for Android 2.2 and other
+   similarly old systems.  */
+
+@SuppressWarnings ("deprecation")
+public class EmacsSdk8Clipboard extends EmacsClipboard
+{
+  private static final String TAG = "EmacsSdk8Clipboard";
+  private ClipboardManager manager;
+
+  public
+  EmacsSdk8Clipboard ()
+  {
+    String what;
+    Context context;
+
+    what = Context.CLIPBOARD_SERVICE;
+    context = EmacsService.SERVICE;
+    manager
+      = (ClipboardManager) context.getSystemService (what);
+  }
+
+  /* Set the clipboard text to CLIPBOARD, a string in UTF-8
+     encoding.  */
+
+  @Override
+  public void
+  setClipboard (byte[] bytes)
+  {
+    try
+      {
+	manager.setText (new String (bytes, "UTF-8"));
+      }
+    catch (UnsupportedEncodingException exception)
+      {
+	Log.w (TAG, "setClipboard: " + exception);
+      }
+  }
+
+  /* Return whether or not Emacs owns the clipboard.  Value is 1 if
+     Emacs does, 0 if Emacs does not, and -1 if that information is
+     unavailable.  */
+
+  @Override
+  public int
+  ownsClipboard ()
+  {
+    return -1;
+  }
+
+  /* Return whether or not clipboard content currently exists.  */
+
+  @Override
+  public boolean
+  clipboardExists ()
+  {
+    return manager.hasText ();
+  }
+
+  /* Return the current content of the clipboard, as plain text, or
+     NULL if no content is available.  */
+
+  @Override
+  public byte[]
+  getClipboard ()
+  {
+    String string;
+    CharSequence text;
+
+    text = manager.getText ();
+
+    if (text == null)
+      return null;
+
+    string = text.toString ();
+
+    try
+      {
+	return string.getBytes ("UTF-8");
+      }
+    catch (UnsupportedEncodingException exception)
+      {
+	Log.w (TAG, "getClipboard: " + exception);
+      }
+
+    return null;
+  }
+};

java/org/gnu/emacs/EmacsView.java

@@ -99,6 +99,9 @@ public class EmacsView extends ViewGroup
      yet responded to.  0 if there is no such outstanding event.  */
   public long pendingConfigure;
 
+  /* Whether or not this view is attached to a window.  */
+  public boolean isAttachedToWindow;
+
   public
   EmacsView (EmacsWindow window)
   {
@@ -140,6 +143,9 @@ public class EmacsView extends ViewGroup
     if (measuredWidth == 0 || measuredHeight == 0)
       return;
 
+    if (!isAttachedToWindow)
+      return;
+
     /* If bitmap is the same width and height as the measured width
        and height, there is no need to do anything.  Avoid allocating
        the extra bitmap.  */
@@ -547,6 +553,8 @@ public class EmacsView extends ViewGroup
   public synchronized void
   onDetachedFromWindow ()
   {
+    isAttachedToWindow = false;
+
     synchronized (this)
       {
 	/* Recycle the bitmap and call GC.  */
@@ -559,6 +567,21 @@ public class EmacsView extends ViewGroup
       }
   }
 
+  @Override
+  public synchronized void
+  onAttachedToWindow ()
+  {
+    isAttachedToWindow = true;
+
+    /* Dirty the bitmap, as it was destroyed when onDetachedFromWindow
+       was called.  */
+    bitmapDirty = true;
+
+    /* Now expose the view contents again.  */
+    EmacsNative.sendExpose (this.window.handle, 0, 0,
+			    measuredWidth, measuredHeight);
+  }
+
   public void
   showOnScreenKeyboard ()
   {