Automatic capitalisation at beginning of sentences

Keep track of end-of-sentence characters while typing and automatically
enable shift when appropriate.

The last few characters just before the cursor need to be queried in
some cases: Begin of input, cursor has moved or text is deleted.
This might have a performance cost.

This normally only enable shift but it also needs to disable shift when
the cursor moves.

5 files changed, 218 insertions, 4 deletions

diff --git a/srcs/juloo.keyboard2/Autocapitalisation.java b/srcs/juloo.keyboard2/Autocapitalisation.java
new file mode 100644
index 0000000..1affdab
--- /dev/null
+++ b/srcs/juloo.keyboard2/Autocapitalisation.java
@@ -0,0 +1,119 @@
+package juloo.keyboard2;
+
+import android.text.InputType;
+import android.text.TextUtils;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
+import android.view.KeyEvent;
+
+final class Autocapitalisation
+{
+  private boolean _enabled = false;
+  private boolean _beginning_of_sentence = false;
+
+  /** Keep track of the cursor to differentiate 'selection_updated' events
+      corresponding to typing from cursor movement. */
+  private int _cursor = 0;
+
+  public boolean should_enable_shift()
+  {
+    return _enabled && _beginning_of_sentence;
+  }
+
+  /** Returns [true] if shift should be on initially. The input connection
+      isn't stored. */
+  public void started(EditorInfo info, InputConnection ic)
+  {
+    if ((info.inputType & InputType.TYPE_TEXT_FLAG_CAP_SENTENCES) == 0)
+    {
+      _enabled = false;
+      return;
+    }
+    _enabled = true;
+    _beginning_of_sentence = ((info.initialCapsMode & TextUtils.CAP_MODE_SENTENCES) != 0);
+    _cursor = 0; // Just a guess
+    scan_text_before_cursor(10, ic);
+  }
+
+  public void typed(CharSequence c)
+  {
+    for (int i = 0; i < c.length(); i++)
+      typed(c.charAt(i));
+  }
+
+  public void typed(char c)
+  {
+    _cursor++;
+    if (is_beginning_of_sentence(c))
+      _beginning_of_sentence = true;
+    else if (!ignore_at_beginning_of_sentence(c))
+      _beginning_of_sentence = false;
+  }
+
+  public void selection_updated(int old_cursor, int new_cursor, InputConnection ic)
+  {
+    if (new_cursor == _cursor)
+      return;
+    // Text has been inserted
+    if (old_cursor == _cursor && new_cursor > old_cursor)
+    {
+      scan_text_before_cursor(Math.min(new_cursor - old_cursor, 10), ic);
+    }
+    else
+    {
+      // Cursor has moved or [_cursor] wasn't uptodate
+      _beginning_of_sentence = false;
+      scan_text_before_cursor(10, ic);
+    }
+    _cursor = new_cursor;
+  }
+
+  /** Updates [_cursor]. */
+  private void scan_text_before_cursor(int range, InputConnection ic)
+  {
+    if (!_enabled) // Don't query characters if disabled
+      return;
+    CharSequence text_before = ic.getTextBeforeCursor(range, 0);
+    if (text_before == null)
+    {
+      _beginning_of_sentence = false;
+    }
+    else
+    {
+      _beginning_of_sentence = true;
+      typed(text_before);
+    }
+  }
+
+  private boolean ignore_at_beginning_of_sentence(char c)
+  {
+    switch (c)
+    {
+      case ' ':
+      case '"':
+      case '\'':
+      case '(':
+      case '«':
+        return true;
+      default:
+        return false;
+    }
+  }
+
+  private boolean is_beginning_of_sentence(char c)
+  {
+    switch (c)
+    {
+      case '.':
+      case ';':
+      case '\n':
+      case '!':
+      case '?':
+      case '¿':
+      case '¡':
+        return true;
+      default:
+        return false;
+    }
+  }
+}
diff --git a/srcs/juloo.keyboard2/Keyboard2.java b/srcs/juloo.keyboard2/Keyboard2.java
index 8483a50..cec2b44 100644
--- a/srcs/juloo.keyboard2/Keyboard2.java
+++ b/srcs/juloo.keyboard2/Keyboard2.java
@@ -35,6 +35,7 @@ public class Keyboard2 extends InputMethodService
   private ViewGroup _emojiPane = null;
 
   private Config _config;
+  private Autocapitalisation _autocap = new Autocapitalisation();
 
   private boolean _debug_logs = false;
 
@@ -57,6 +58,14 @@ public class Keyboard2 extends InputMethodService
     _debug_logs = getResources().getBoolean(R.bool.debug_logs);
   }
 
+  private void update_shift_state(boolean might_disable)
+  {
+    if (_autocap.should_enable_shift())
+      _keyboardView.set_shift_state(true);
+    else if (might_disable)
+      _keyboardView.set_shift_state(false);
+  }
+
   private List<InputMethodSubtype> getEnabledSubtypes(InputMethodManager imm)
   {
     String pkg = getPackageName();
@@ -163,7 +172,7 @@ public class Keyboard2 extends InputMethodService
     return getResources().getString(res);
   }
 
-  private void refreshEditorInfo(EditorInfo info)
+  private void refresh_action_label(EditorInfo info)
   {
     // First try to look at 'info.actionLabel', if it isn't set, look at
     // 'imeOptions'.
@@ -210,11 +219,13 @@ public class Keyboard2 extends InputMethodService
   public void onStartInputView(EditorInfo info, boolean restarting)
   {
     refreshConfig();
-    refreshEditorInfo(info);
+    refresh_action_label(info);
     if ((info.inputType & InputType.TYPE_CLASS_NUMBER) != 0)
       _keyboardView.setKeyboard(getLayout(R.xml.numeric));
     else
       _keyboardView.setKeyboard(getLayout(_currentTextLayout));
+    _autocap.started(info, getCurrentInputConnection());
+    update_shift_state(false);
     setInputView(_keyboardView);
     if (_debug_logs)
       log_editor_info(info);
@@ -237,6 +248,14 @@ public class Keyboard2 extends InputMethodService
   }
 
   @Override
+  public void onUpdateSelection(int oldSelStart, int oldSelEnd, int newSelStart, int newSelEnd, int candidatesStart, int candidatesEnd)
+  {
+    super.onUpdateSelection(oldSelStart, oldSelEnd, newSelStart, newSelEnd, candidatesStart, candidatesEnd);
+    _autocap.selection_updated(oldSelStart, newSelStart, getCurrentInputConnection());
+    update_shift_state(true);
+  }
+
+  @Override
   public void onFinishInputView(boolean finishingInput)
   {
     super.onFinishInputView(finishingInput);
@@ -330,11 +349,15 @@ public class Keyboard2 extends InputMethodService
     public void commitText(String text)
     {
       getCurrentInputConnection().commitText(text, 1);
+      _autocap.typed(text);
+      update_shift_state(false);
     }
 
     public void commitChar(char c)
     {
       sendKeyChar(c);
+      _autocap.typed(c);
+      update_shift_state(false);
     }
   }
 
diff --git a/srcs/juloo.keyboard2/Keyboard2View.java b/srcs/juloo.keyboard2/Keyboard2View.java
index fed2be6..d946aa1 100644
--- a/srcs/juloo.keyboard2/Keyboard2View.java
+++ b/srcs/juloo.keyboard2/Keyboard2View.java
@@ -90,6 +90,27 @@ public class Keyboard2View extends View
     invalidate();
   }
 
+  /** Called by auto-capitalisation. */
+  public void set_shift_state(boolean state)
+  {
+    KeyValue shift = KeyValue.getKeyByName("shift");
+    KeyboardData.Key key = _keyboard.findKeyWithValue(shift);
+    if (key == null)
+    {
+      // Lookup again for the lockable shift key, which is a different value.
+      shift = shift.withFlags(shift.getFlags() | KeyValue.FLAG_LOCK);
+      key = _keyboard.findKeyWithValue(shift);
+    }
+    if (key != null)
+    {
+      if (state)
+        _pointers.add_fake_pointer(shift, key);
+      else
+        _pointers.remove_fake_pointer(shift, key);
+      invalidate();
+    }
+  }
+
   public KeyValue modifyKey(KeyValue k, Pointers.Modifiers mods)
   {
     return KeyModifier.modify(k, mods);
diff --git a/srcs/juloo.keyboard2/KeyboardData.java b/srcs/juloo.keyboard2/KeyboardData.java
index c95dc51..9b47152 100644
--- a/srcs/juloo.keyboard2/KeyboardData.java
+++ b/srcs/juloo.keyboard2/KeyboardData.java
@@ -43,6 +43,17 @@ class KeyboardData
     return new KeyboardData(rows, keysWidth, extra_keys);
   }
 
+  public Key findKeyWithValue(KeyValue kv)
+  {
+    for (Row r : rows)
+    {
+      Key k = r.findKeyWithValue(kv);
+      if (k != null)
+        return k;
+    }
+    return null;
+  }
+
   private static void addExtraKeys_to_row(ArrayList<Row> rows, final Iterator<KeyValue> extra_keys, int row_i, final int d)
   {
     if (!extra_keys.hasNext())
@@ -168,6 +179,14 @@ class KeyboardData
         public Key apply(Key k) { return k.scaleWidth(s); }
       });
     }
+
+    public Key findKeyWithValue(KeyValue kv)
+    {
+      for (Key k : keys)
+        if (k.hasValue(kv))
+          return k;
+      return null;
+    }
   }
 
   public static class Key
@@ -291,6 +310,17 @@ class KeyboardData
       }
       return (c == null) ? null : c.kv;
     }
+
+    public boolean hasValue(KeyValue kv)
+    {
+      return (hasValue(key0, kv) || hasValue(key1, kv) || hasValue(key2, kv) ||
+          hasValue(key3, kv) || hasValue(key4, kv));
+    }
+
+    private static boolean hasValue(Corner c, KeyValue kv)
+    {
+      return (c != null && c.kv.equals(kv));
+    }
   }
 
   public static final class Corner
diff --git a/srcs/juloo.keyboard2/Pointers.java b/srcs/juloo.keyboard2/Pointers.java
index 9b8ee97..84323ae 100644
--- a/srcs/juloo.keyboard2/Pointers.java
+++ b/srcs/juloo.keyboard2/Pointers.java
@@ -74,6 +74,24 @@ public final class Pointers implements Handler.Callback
     return -1;
   }
 
+  /** Fake pointers are latched and not lockable. */
+  public void add_fake_pointer(KeyValue kv, KeyboardData.Key key)
+  {
+    // Avoid adding a fake pointer to a key that is already down.
+    if (isKeyDown(key))
+      return;
+    Pointer ptr = new Pointer(-1, key, kv, 0.f, 0.f, Modifiers.EMPTY);
+    ptr.flags = ptr.flags & ~(KeyValue.FLAG_LATCH | KeyValue.FLAG_LOCK);
+    _ptrs.add(ptr);
+  }
+
+  public void remove_fake_pointer(KeyValue kv, KeyboardData.Key key)
+  {
+    Pointer ptr = getLatched(key, kv);
+    if (ptr != null)
+      removePtr(ptr);
+  }
+
   // Receiving events
 
   public void onTouchUp(int pointerId)
@@ -252,8 +270,11 @@ public final class Pointers implements Handler.Callback
 
   private Pointer getLatched(Pointer target)
   {
-    KeyboardData.Key k = target.key;
-    KeyValue v = target.value;
+    return getLatched(target.key, target.value);
+  }
+
+  private Pointer getLatched(KeyboardData.Key k, KeyValue v)
+  {
     if (v == null)
       return null;
     for (Pointer p : _ptrs)