Port Emacs to Android 34

* configure.ac: Detect and require Android 34 headers.

* doc/emacs/android.texi (Android Environment): Mention new
permissions mandated by Android 34.

* java/AndroidManifest.xml.in: Introduce new permissions and
foreground service types prerequisite for background execution under
Android 34.

* java/INSTALL: Update installation documentation.

* java/org/gnu/emacs/EmacsSdk7FontDriver.java (Sdk7FontEntity)
(Sdk7FontObject):

* java/org/gnu/emacs/EmacsService.java (onCreate): Silence deprecation
warnings.

* src/android.c: Update documentation.

4 files changed, 29 insertions, 7 deletions

diff --git a/java/AndroidManifest.xml.in b/java/AndroidManifest.xml.in
index 9ba9dabde81..2749f43c245 100644
--- a/java/AndroidManifest.xml.in
+++ b/java/AndroidManifest.xml.in
@@ -73,8 +73,12 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>. -->
 
   <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
 
+  <!-- Under Android 14 or later to run within the background.  -->
+
+  <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE"/>
+
   <uses-sdk android:minSdkVersion="@ANDROID_MIN_SDK@"
-            android:targetSdkVersion="33"/>
+            android:targetSdkVersion="34"/>
 
   <application android:name="org.gnu.emacs.EmacsApplication"
                android:label="Emacs"
@@ -190,6 +194,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>. -->
              android:directBootAware="false"
              android:enabled="true"
              android:exported="false"
+             android:foregroundServiceType="specialUse"
              android:label="GNU Emacs service"/>
   </application>
 </manifest>
diff --git a/java/INSTALL b/java/INSTALL
index fb235af1346..b6c31483dd3 100644
--- a/java/INSTALL
+++ b/java/INSTALL
@@ -39,7 +39,7 @@ script like so:
 Replacing the paths in the command line above with:
 
   - the path to the `android.jar' headers which come with the Android
-    SDK.  They must correspond to Android version 13 (API level 33).
+    SDK.  They must correspond to Android version 14 (API level 34).
 
   - the path to the C compiler in the Android NDK, for the kind of CPU
     you are building Emacs to run on.
@@ -87,13 +87,13 @@ necessary for compiling Emacs.
 
 It is imperative that Emacs is compiled using the headers for the
 exact API level that it is written for.  This is currently API level
-33, so the correct android.jar archive is located within a directory
-whose name begins with `android-33'.  Minor revisions to the headers
+34, so the correct android.jar archive is located within a directory
+whose name begins with `android-34'.  Minor revisions to the headers
 are inconsequential towards the Emacs compilation process; if there is
-a directory named `android-33-extN' (where N represents a revision to
+a directory named `android-34-extN' (where N represents a revision to
 the Android SDK), whether you provide `configure' with that
 directory's android.jar or the android.jar contained within the
-directory named `android-33' is of no special importance.
+directory named `android-34' is of no special importance.
 
 The ndk directory contains one subdirectory for each version of the
 Android NDK installed.  This directory in turn contains the C and C++
diff --git a/java/org/gnu/emacs/EmacsSdk7FontDriver.java b/java/org/gnu/emacs/EmacsSdk7FontDriver.java
index 21ae159d5bd..33d6ee34fa4 100644
--- a/java/org/gnu/emacs/EmacsSdk7FontDriver.java
+++ b/java/org/gnu/emacs/EmacsSdk7FontDriver.java
@@ -99,6 +99,7 @@ public class EmacsSdk7FontDriver extends EmacsFontDriver
     /* The typeface.  */
     public Sdk7Typeface typeface;
 
+    @SuppressWarnings ("deprecation")
     public
     Sdk7FontEntity (Sdk7Typeface typeface)
     {
@@ -120,6 +121,7 @@ public class EmacsSdk7FontDriver extends EmacsFontDriver
     /* The typeface.  */
     public Sdk7Typeface typeface;
 
+    @SuppressWarnings ("deprecation")
     public
     Sdk7FontObject (Sdk7Typeface typeface, int pixelSize)
     {
diff --git a/java/org/gnu/emacs/EmacsService.java b/java/org/gnu/emacs/EmacsService.java
index 997c6923fcc..28b725d0cd0 100644
--- a/java/org/gnu/emacs/EmacsService.java
+++ b/java/org/gnu/emacs/EmacsService.java
@@ -223,6 +223,21 @@ public final class EmacsService extends Service
       }
   }
 
+  /* Return the display density, adjusted in accord with the user's
+     text scaling preferences.  */
+
+  @SuppressWarnings ("deprecation")
+  private static float
+  getScaledDensity (DisplayMetrics metrics)
+  {
+    /* The scaled density has been made obsolete by the introduction
+       of non-linear text scaling in Android 34, where there is no
+       longer a fixed relation between point and pixel sizes, but
+       remains useful, considering that Emacs does not support
+       non-linear text scaling.  */
+    return metrics.scaledDensity;
+  }
+
   @Override
   public void
   onCreate ()
@@ -242,7 +257,7 @@ public final class EmacsService extends Service
     metrics = getResources ().getDisplayMetrics ();
     pixelDensityX = metrics.xdpi;
     pixelDensityY = metrics.ydpi;
-    tempScaledDensity = ((metrics.scaledDensity
+    tempScaledDensity = ((getScaledDensity (metrics)
                           / metrics.density)
                          * pixelDensityX);
     resolver = getContentResolver ();