Voice IME chooser popup

Bring a popup for choosing the voice IME when the voice key is pressed
for the first time or the list of voice IMEs installed on the device
change.

A preference stores the last selected IME and the last seen list of
IMEs.

5 files changed, 182 insertions, 35 deletions

diff --git a/srcs/juloo.keyboard2/Config.java b/srcs/juloo.keyboard2/Config.java
index 31fe0b0..f8b2070 100644
--- a/srcs/juloo.keyboard2/Config.java
+++ b/srcs/juloo.keyboard2/Config.java
@@ -389,6 +389,11 @@ final class Config
     return _globalConfig;
   }
 
+  public static SharedPreferences globalPrefs()
+  {
+    return _globalConfig._prefs;
+  }
+
   public static interface IKeyEventHandler
   {
     public void key_down(KeyValue value, boolean is_swipe);
diff --git a/srcs/juloo.keyboard2/Keyboard2.java b/srcs/juloo.keyboard2/Keyboard2.java
index d045396..0e91f8c 100644
--- a/srcs/juloo.keyboard2/Keyboard2.java
+++ b/srcs/juloo.keyboard2/Keyboard2.java
@@ -151,7 +151,7 @@ public class Keyboard2 extends InputMethodService
       _config.shouldOfferSwitchingToNextInputMethod = true;
     else
       _config.shouldOfferSwitchingToNextInputMethod = shouldOfferSwitchingToNextInputMethod();
-    _config.shouldOfferVoiceTyping = (get_voice_typing_im(imm) != null);
+    _config.shouldOfferVoiceTyping = true;
     KeyboardData default_layout = null;
     _config.extra_keys_subtype = null;
     if (VERSION.SDK_INT >= 12)
@@ -224,20 +224,6 @@ public class Keyboard2 extends InputMethodService
     _keyboardView.reset();
   }
 
-  /** Returns the id and subtype of the voice typing IM. Returns [null] if none
-      is installed or if the feature is unsupported. */
-  SimpleEntry<String, InputMethodSubtype> get_voice_typing_im(InputMethodManager imm)
-  {
-    if (VERSION.SDK_INT < 11) // Due to InputMethodSubtype
-      return null;
-    for (InputMethodInfo im : imm.getEnabledInputMethodList())
-      for (InputMethodSubtype imst : imm.getEnabledInputMethodSubtypeList(im, true))
-        // Switch to the first IM that has a subtype of this mode
-        if (imst.getMode().equals("voice"))
-          return new SimpleEntry(im.getId(), imst);
-    return null;
-  }
-
   private KeyboardData refresh_special_layout(EditorInfo info)
   {
     switch (info.inputType & InputType.TYPE_MASK_CLASS)
@@ -433,14 +419,9 @@ public class Keyboard2 extends InputMethodService
           break;
 
         case SWITCH_VOICE_TYPING:
-          SimpleEntry<String, InputMethodSubtype> im = get_voice_typing_im(get_imm());
-          if (im == null)
-            return;
-          // Best-effort. Good enough for triggering Google's voice typing.
-          if (VERSION.SDK_INT < 28)
-            switchInputMethod(im.getKey());
-          else
-            switchInputMethod(im.getKey(), im.getValue());
+          if (!VoiceImeSwitcher.switch_to_voice_ime(Keyboard2.this, get_imm(),
+                Config.globalPrefs()))
+            _config.shouldOfferVoiceTyping = false;
           break;
       }
     }
diff --git a/srcs/juloo.keyboard2/StringUtils.java b/srcs/juloo.keyboard2/StringUtils.java
deleted file mode 100644
index 2994509..0000000
--- a/srcs/juloo.keyboard2/StringUtils.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package juloo.keyboard2;
-
-final class Utils
-{
-  /** Turn the first letter of a string uppercase. */
-  public static String capitalize_string(String s)
-  {
-    // Make sure not to cut a code point in half
-    int i = s.offsetByCodePoints(0, 1);
-    return s.substring(0, i).toUpperCase() + s.substring(i);
-  }
-}
diff --git a/srcs/juloo.keyboard2/Utils.java b/srcs/juloo.keyboard2/Utils.java
new file mode 100644
index 0000000..cd28dfa
--- /dev/null
+++ b/srcs/juloo.keyboard2/Utils.java
@@ -0,0 +1,30 @@
+package juloo.keyboard2;
+
+import android.app.AlertDialog;
+import android.os.IBinder;
+import android.view.Window;
+import android.view.WindowManager;
+
+class Utils
+{
+  /** Turn the first letter of a string uppercase. */
+  public static String capitalize_string(String s)
+  {
+    // Make sure not to cut a code point in half
+    int i = s.offsetByCodePoints(0, 1);
+    return s.substring(0, i).toUpperCase() + s.substring(i);
+  }
+
+  /** Like [dialog.show()] but properly configure layout params when called
+      from an IME. [token] is the input view's [getWindowToken()]. */
+  public static void show_dialog_on_ime(AlertDialog dialog, IBinder token)
+  {
+    Window win = dialog.getWindow();
+    WindowManager.LayoutParams lp = win.getAttributes();
+    lp.token = token;
+    lp.type = WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;
+    win.setAttributes(lp);
+    win.addFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);
+    dialog.show();
+  }
+}
diff --git a/srcs/juloo.keyboard2/VoiceImeSwitcher.java b/srcs/juloo.keyboard2/VoiceImeSwitcher.java
new file mode 100644
index 0000000..7ddda5e
--- /dev/null
+++ b/srcs/juloo.keyboard2/VoiceImeSwitcher.java
@@ -0,0 +1,143 @@
+package juloo.keyboard2;
+
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.SharedPreferences;
+import android.content.res.Resources;
+import android.inputmethodservice.InputMethodService;
+import android.os.Build.VERSION;
+import android.view.inputmethod.InputMethodInfo;
+import android.view.inputmethod.InputMethodManager;
+import android.view.inputmethod.InputMethodSubtype;
+import android.widget.ArrayAdapter;
+import java.util.AbstractMap.SimpleEntry;
+import java.util.ArrayList;
+import java.util.List;
+
+class VoiceImeSwitcher
+{
+  static final String PREF_LAST_USED = "voice_ime_last_used";
+  static final String PREF_KNOWN_IMES = "voice_ime_known";
+
+  /** Switch to the voice ime. This might open a chooser popup. Preferences are
+      used to store the last selected voice ime and to detect whether the
+      chooser popup must be shown. Returns [false] if the detection failed and
+      is unlikely to succeed. */
+  public static boolean switch_to_voice_ime(InputMethodService ims,
+      InputMethodManager imm, SharedPreferences prefs)
+  {
+    if (VERSION.SDK_INT < 11) // Due to InputMethodSubtype
+      return false;
+    List<IME> imes = get_voice_ime_list(imm);
+    String last_used = prefs.getString(PREF_LAST_USED, null);
+    String last_known_imes = prefs.getString(PREF_KNOWN_IMES, null);
+    IME last_used_ime = get_ime_by_id(imes, last_used);
+    if (imes.size() == 0)
+      return false;
+    if (last_used == null || last_known_imes == null || last_used_ime == null
+        || !last_known_imes.equals(serialize_ime_ids(imes)))
+      choose_voice_ime_and_update_prefs(ims, prefs, imes);
+    else
+      switch_input_method(ims, last_used_ime);
+    return true;
+  }
+
+  /** Show the voice IME chooser popup and switch to the selected IME.
+      Preferences are updated so that future calls to [switch_to_voice_ime]
+      switch to the newly selected IME. */
+  static void choose_voice_ime_and_update_prefs(final InputMethodService ims,
+      final SharedPreferences prefs, final List<IME> imes)
+  {
+    List<String> ime_display_names = get_ime_display_names(ims, imes);
+    ArrayAdapter layouts = new ArrayAdapter(ims, android.R.layout.simple_list_item_1, ime_display_names);
+    AlertDialog dialog = new AlertDialog.Builder(ims)
+      .setAdapter(layouts, new DialogInterface.OnClickListener(){
+        public void onClick(DialogInterface _dialog, int which)
+        {
+          IME selected = imes.get(which);
+          prefs.edit()
+            .putString(PREF_LAST_USED, selected.get_id())
+            .putString(PREF_KNOWN_IMES, serialize_ime_ids(imes))
+            .commit();
+          switch_input_method(ims, selected);
+        }
+      })
+      .create();
+    Utils.show_dialog_on_ime(dialog, ims.getWindow().getWindow().getDecorView().getWindowToken());
+  }
+
+  static void switch_input_method(InputMethodService ims, IME ime)
+  {
+    if (VERSION.SDK_INT < 28)
+      ims.switchInputMethod(ime.get_id());
+    else
+      ims.switchInputMethod(ime.get_id(), ime.subtype);
+  }
+
+  static IME get_ime_by_id(List<IME> imes, String id)
+  {
+    if (id != null)
+      for (IME ime : imes)
+        if (ime.get_id().equals(id))
+          return ime;
+    return null;
+  }
+
+  static List<String> get_ime_display_names(InputMethodService ims, List<IME> imes)
+  {
+    List<String> names = new ArrayList<String>();
+    for (IME ime : imes)
+      names.add(ime.get_display_name(ims));
+    return names;
+  }
+
+  static List<IME> get_voice_ime_list(InputMethodManager imm)
+  {
+    List<IME> imes = new ArrayList<IME>();
+    for (InputMethodInfo im : imm.getEnabledInputMethodList())
+      for (InputMethodSubtype imst : imm.getEnabledInputMethodSubtypeList(im, true))
+        if (imst.getMode().equals("voice"))
+          imes.add(new IME(im, imst));
+    return imes;
+  }
+
+  /** The chooser popup is shown whether this string changes. */
+  static String serialize_ime_ids(List<IME> imes)
+  {
+    StringBuilder b = new StringBuilder();
+    for (IME ime : imes)
+    {
+      b.append(ime.get_id());
+      b.append(',');
+    }
+    return b.toString();
+  }
+
+  static class IME
+  {
+    public final InputMethodInfo im;
+    public final InputMethodSubtype subtype;
+
+    IME(InputMethodInfo im_, InputMethodSubtype st)
+    {
+      im = im_;
+      subtype = st;
+    }
+
+    String get_id() { return im.getId(); }
+
+    /** Localised display name. */
+    String get_display_name(Context ctx)
+    {
+      String subtype_name = "";
+      if (VERSION.SDK_INT >= 14)
+      {
+        subtype_name = subtype.getDisplayName(ctx, im.getPackageName(), null).toString();
+        if (!subtype_name.equals(""))
+          subtype_name = " - " + subtype_name;
+      }
+      return im.loadLabel(ctx.getPackageManager()).toString() + subtype_name;
+    }
+  }
+}