Update Android port

* java/org/gnu/emacs/EmacsContextMenu.java (display): Use
`EmacsHolder' instead of `Holder'.
* java/org/gnu/emacs/EmacsDialog.java (toAlertDialog): Use
`EmacsDialogButtonLayout' to ensure that buttons are wrapped
properly.
(display): Adjust for new holder class.
* java/org/gnu/emacs/EmacsDialogButtonLayout.java
(EmacsDialogButtonLayout, onMeasure, onLayout): New functions.

* java/org/gnu/emacs/EmacsDrawLine.java:
* java/org/gnu/emacs/EmacsFillPolygon.java: Remove redundant
imports.
* java/org/gnu/emacs/EmacsHolder.java (EmacsHolder<T>):
* java/org/gnu/emacs/EmacsService.java (class Holder<T>)
(getEmacsView, EmacsService): Rename `Holder' to `EmacsHolder'
and make it public.

7 files changed, 195 insertions, 25 deletions

diff --git a/java/org/gnu/emacs/EmacsContextMenu.java b/java/org/gnu/emacs/EmacsContextMenu.java
index 5bae41bd61d..60f2db67fb0 100644
--- a/java/org/gnu/emacs/EmacsContextMenu.java
+++ b/java/org/gnu/emacs/EmacsContextMenu.java
@@ -331,9 +331,9 @@ public final class EmacsContextMenu
            final int yPosition, final int serial)
   {
     Runnable runnable;
-    final Holder<Boolean> rc;
+    final EmacsHolder<Boolean> rc;
 
-    rc = new Holder<Boolean> ();
+    rc = new EmacsHolder<Boolean> ();
 
     runnable = new Runnable () {
         @Override
diff --git a/java/org/gnu/emacs/EmacsDialog.java b/java/org/gnu/emacs/EmacsDialog.java
index 3a5f22021fc..afdce3c50ec 100644
--- a/java/org/gnu/emacs/EmacsDialog.java
+++ b/java/org/gnu/emacs/EmacsDialog.java
@@ -150,7 +150,7 @@ public final class EmacsDialog implements DialogInterface.OnDismissListener
     AlertDialog dialog;
     int size;
     EmacsButton button;
-    LinearLayout layout;
+    EmacsDialogButtonLayout layout;
     Button buttonView;
     ViewGroup.LayoutParams layoutParams;
 
@@ -192,19 +192,16 @@ public final class EmacsDialog implements DialogInterface.OnDismissListener
       }
     else
       {
-        /* There are more than 4 buttons.  Add them all to a
-           LinearLayout.  */
-        layout = new LinearLayout (context);
-        layoutParams
-          = new LinearLayout.LayoutParams (ViewGroup.LayoutParams.WRAP_CONTENT,
-                                           ViewGroup.LayoutParams.WRAP_CONTENT);
+        /* There are more than 3 buttons.  Add them all to a special
+           container widget that handles wrapping.  */
+
+        layout = new EmacsDialogButtonLayout (context);
 
         for (EmacsButton emacsButton : buttons)
           {
             buttonView = new Button (context);
             buttonView.setText (emacsButton.name);
             buttonView.setOnClickListener (emacsButton);
-            buttonView.setLayoutParams (layoutParams);
             buttonView.setEnabled (emacsButton.enabled);
             layout.addView (buttonView);
           }
@@ -336,9 +333,9 @@ public final class EmacsDialog implements DialogInterface.OnDismissListener
   display ()
   {
     Runnable runnable;
-    final Holder<Boolean> rc;
+    final EmacsHolder<Boolean> rc;
 
-    rc = new Holder<Boolean> ();
+    rc = new EmacsHolder<Boolean> ();
     runnable = new Runnable () {
         @Override
         public void
diff --git a/java/org/gnu/emacs/EmacsDialogButtonLayout.java b/java/org/gnu/emacs/EmacsDialogButtonLayout.java
new file mode 100644
index 00000000000..5d97eea32aa
--- /dev/null
+++ b/java/org/gnu/emacs/EmacsDialogButtonLayout.java
@@ -0,0 +1,152 @@
+/* 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.Context;
+
+import android.view.View;
+import android.view.View.MeasureSpec;
+import android.view.ViewGroup;
+
+
+
+/* This ``view group'' implements a container widget for multiple
+   buttons of the type found in pop-up dialogs.  It is used when
+   displaying a dialog box that contains more than three buttons, as
+   the default dialog box widget is not capable of holding more than
+   that many.  */
+
+
+
+public class EmacsDialogButtonLayout extends ViewGroup
+{
+  public
+  EmacsDialogButtonLayout (Context context)
+  {
+    super (context);
+  }
+
+  @Override
+  protected void
+  onMeasure (int widthMeasureSpec, int heightMeasureSpec)
+  {
+    int width, count, i, x, y, height, spec, tempSpec;
+    View view;
+
+    /* Obtain the width of this widget and create the measure
+       specification used to measure children.  */
+
+    width = MeasureSpec.getSize (widthMeasureSpec);
+    spec = MeasureSpec.makeMeasureSpec (0, MeasureSpec.UNSPECIFIED);
+    tempSpec
+      = MeasureSpec.makeMeasureSpec (width, MeasureSpec.AT_MOST);
+    x = y = height = 0;
+
+    /* Run through each widget.  */
+
+    count = getChildCount ();
+
+    for (i = 0; i < count; ++i)
+      {
+        view = getChildAt (i);
+
+        /* Measure this view.  */
+        view.measure (spec, spec);
+
+        if (width - x < view.getMeasuredWidth ())
+          {
+            /* Move onto the next line, unless this line is empty.  */
+
+            if (x != 0)
+              {
+                y += height;
+                height = x = 0;
+              }
+
+            if (view.getMeasuredWidth () > width)
+              /* Measure the view again, this time forcing it to be at
+                 most width wide, if it is not already.  */
+              view.measure (tempSpec, spec);
+          }
+
+        height = Math.max (height, view.getMeasuredHeight ());
+        x += view.getMeasuredWidth ();
+      }
+
+    /* Now set the measured size of this widget.  */
+    setMeasuredDimension (width, y + height);
+  }
+
+  @Override
+  protected void
+  onLayout (boolean changed, int left, int top, int right,
+            int bottom)
+  {
+    int width, count, i, x, y, height, spec, tempSpec;
+    View view;
+
+    /* Obtain the width of this widget and create the measure
+       specification used to measure children.  */
+
+    width = getMeasuredWidth ();
+    spec = MeasureSpec.makeMeasureSpec (0, MeasureSpec.UNSPECIFIED);
+    tempSpec
+      = MeasureSpec.makeMeasureSpec (width, MeasureSpec.AT_MOST);
+    x = y = height = 0;
+
+    /* Run through each widget.  */
+
+    count = getChildCount ();
+
+    for (i = 0; i < count; ++i)
+      {
+        view = getChildAt (i);
+
+        /* Measure this view.  */
+        view.measure (spec, spec);
+
+        if (width - x < view.getMeasuredWidth ())
+          {
+            /* Move onto the next line, unless this line is empty.  */
+
+            if (x != 0)
+              {
+                y += height;
+                height = x = 0;
+              }
+
+            if (view.getMeasuredWidth () > width)
+              /* Measure the view again, this time forcing it to be at
+                 most width wide, if it is not already.  */
+              view.measure (tempSpec, spec);
+          }
+
+        /* Now assign this view its position.  */
+        view.layout (x, y, x + view.getMeasuredWidth (),
+                     y + view.getMeasuredHeight ());
+
+        /* And move on to the next widget.  */
+        height = Math.max (height, view.getMeasuredHeight ());
+        x += view.getMeasuredWidth ();
+      }
+  }
+};
diff --git a/java/org/gnu/emacs/EmacsDrawLine.java b/java/org/gnu/emacs/EmacsDrawLine.java
index 92e03c48e26..3f5067c0bdd 100644
--- a/java/org/gnu/emacs/EmacsDrawLine.java
+++ b/java/org/gnu/emacs/EmacsDrawLine.java
@@ -19,8 +19,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 package org.gnu.emacs;
 
-import java.lang.Math;
-
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Rect;
diff --git a/java/org/gnu/emacs/EmacsFillPolygon.java b/java/org/gnu/emacs/EmacsFillPolygon.java
index ea8324c543c..4ae3882cab4 100644
--- a/java/org/gnu/emacs/EmacsFillPolygon.java
+++ b/java/org/gnu/emacs/EmacsFillPolygon.java
@@ -19,8 +19,6 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 package org.gnu.emacs;
 
-import java.lang.Math;
-
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Path;
diff --git a/java/org/gnu/emacs/EmacsHolder.java b/java/org/gnu/emacs/EmacsHolder.java
new file mode 100644
index 00000000000..3ca803d1640
--- /dev/null
+++ b/java/org/gnu/emacs/EmacsHolder.java
@@ -0,0 +1,30 @@
+/* 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;
+
+
+
+/* This class serves as a simple reference to an object of type T.
+   Nothing could be found inside the standard library.  */
+
+public class EmacsHolder<T>
+{
+  T thing;
+};
diff --git a/java/org/gnu/emacs/EmacsService.java b/java/org/gnu/emacs/EmacsService.java
index 6d70536faf0..2074a5b7c2b 100644
--- a/java/org/gnu/emacs/EmacsService.java
+++ b/java/org/gnu/emacs/EmacsService.java
@@ -71,11 +71,6 @@ import android.util.DisplayMetrics;
 
 import android.widget.Toast;
 
-class Holder<T>
-{
-  T thing;
-};
-
 /* EmacsService is the service that starts the thread running Emacs
    and handles requests by that Emacs instance.  */
 
@@ -282,9 +277,9 @@ public final class EmacsService extends Service
                 final boolean isFocusedByDefault)
   {
     Runnable runnable;
-    final Holder<EmacsView> view;
+    final EmacsHolder<EmacsView> view;
 
-    view = new Holder<EmacsView> ();
+    view = new EmacsHolder<EmacsView> ();
 
     runnable = new Runnable () {
         public void
@@ -604,10 +599,10 @@ public final class EmacsService extends Service
   public ClipboardManager
   getClipboardManager ()
   {
-    final Holder<ClipboardManager> manager;
+    final EmacsHolder<ClipboardManager> manager;
     Runnable runnable;
 
-    manager = new Holder<ClipboardManager> ();
+    manager = new EmacsHolder<ClipboardManager> ();
 
     runnable = new Runnable () {
         public void