Add support for delete swipe and spacebar navigation.

This is taken from simplekeyboard; the spacebar logic is the old one, to avoid a bug in some applications when moving the cursor at the beginning of the text.

app/src/main/AndroidManifest.xml

@@ -19,11 +19,9 @@
         package="org.dslul.openboard.inputmethod.latin">
 
     <uses-permission android:name="android.permission.READ_CONTACTS" />
-    <uses-permission android:name="android.permission.READ_PROFILE" />
     <uses-permission android:name="android.permission.READ_USER_DICTIONARY" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.VIBRATE" />
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.WRITE_USER_DICTIONARY" />
 
     <!-- A signature-protected permission to ask AOSP Keyboard to close the software keyboard.

app/src/main/java/org/dslul/openboard/inputmethod/keyboard/KeyboardActionListener.java

@@ -100,6 +100,9 @@ public interface KeyboardActionListener {
      * @return true if the request has been consumed, false otherwise.
      */
     public boolean onCustomRequest(int requestCode);
+    public void onMovePointer(int steps);
+    public void onMoveDeletePointer(int steps);
+    public void onUpWithDeletePointerActive();
 
     public static final KeyboardActionListener EMPTY_LISTENER = new Adapter();
 
@@ -128,5 +131,11 @@ public interface KeyboardActionListener {
         public boolean onCustomRequest(int requestCode) {
             return false;
         }
+        @Override
+        public void onMovePointer(int steps) {}
+        @Override
+        public void onMoveDeletePointer(int steps) {}
+        @Override
+        public void onUpWithDeletePointerActive() {}
     }
 }

app/src/main/java/org/dslul/openboard/inputmethod/keyboard/PointerTracker.java

@@ -85,6 +85,7 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
 
     // Parameters for pointer handling.
     private static PointerTrackerParams sParams;
+    private static int sPointerStep = (int)(10.0 * Resources.getSystem().getDisplayMetrics().density);
     private static GestureStrokeRecognitionParams sGestureStrokeRecognitionParams;
     private static GestureStrokeDrawingParams sGestureStrokeDrawingParams;
     private static boolean sNeedsPhantomSuddenMoveEventHack;
@@ -127,6 +128,10 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
     // Last pointer position.
     private int mLastX;
     private int mLastY;
+    private int mStartX;
+    private int mStartY;
+    private long mStartTime;
+    private boolean mCursorMoved = false;
 
     // true if keyboard layout has been changed.
     private boolean mKeyboardLayoutHasBeenChanged;
@@ -696,6 +701,9 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
             startRepeatKey(key);
             startLongPressTimer(key);
             setPressedKeyGraphics(key, eventTime);
+            mStartX = x;
+            mStartY = y;
+            mStartTime = System.currentTimeMillis();
         }
     }
 
@@ -894,10 +902,35 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
     }
 
     private void onMoveEventInternal(final int x, final int y, final long eventTime) {
+        final Key oldKey = mCurrentKey;
+
+        if (oldKey != null && oldKey.getCode() == Constants.CODE_SPACE && Settings.getInstance().getCurrent().mSpaceTrackpadEnabled) {
+            //Pointer slider
+            int steps = (x - mStartX) / sPointerStep;
+            final int longpressTimeout = Settings.getInstance().getCurrent().mKeyLongpressTimeout / MULTIPLIER_FOR_LONG_PRESS_TIMEOUT_IN_SLIDING_INPUT;
+            if (steps != 0 && mStartTime + longpressTimeout < System.currentTimeMillis()) {
+                mCursorMoved = true;
+                mStartX += steps * sPointerStep;
+                sListener.onMovePointer(steps);
+            }
+            return;
+        }
+
+        if (oldKey != null && oldKey.getCode() == Constants.CODE_DELETE && Settings.getInstance().getCurrent().mDeleteSwipeEnabled) {
+            //Delete slider
+            int steps = (x - mStartX) / sPointerStep;
+            if (steps != 0) {
+                sTimerProxy.cancelKeyTimersOf(this);
+                mCursorMoved = true;
+                mStartX += steps * sPointerStep;
+                sListener.onMoveDeletePointer(steps);
+            }
+            return;
+        }
+
+        final Key newKey = onMoveKey(x, y);
         final int lastX = mLastX;
         final int lastY = mLastY;
-        final Key oldKey = mCurrentKey;
-        final Key newKey = onMoveKey(x, y);
 
         if (sGestureEnabler.shouldHandleGesture()) {
             // Register move event on gesture tracker.
@@ -971,6 +1004,10 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
         // Release the last pressed key.
         setReleasedKeyGraphics(currentKey, true /* withAnimation */);
 
+        if(mCursorMoved && currentKey.getCode() == Constants.CODE_DELETE) {
+            sListener.onUpWithDeletePointerActive();
+        }
+
         if (isShowingMoreKeysPanel()) {
             if (!mIsTrackingForActionDisabled) {
                 final int translatedX = mMoreKeysPanel.translateX(x);
@@ -981,6 +1018,11 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
             return;
         }
 
+        if (mCursorMoved) {
+            mCursorMoved = false;
+            return;
+        }
+
         if (sInGesture) {
             if (currentKey != null) {
                 callListenerOnRelease(currentKey, currentKey.getCode(), true /* withSliding */);
@@ -1023,6 +1065,9 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
         if (isShowingMoreKeysPanel()) {
             return;
         }
+        if(mCursorMoved) {
+            return;
+        }
         final Key key = getKey();
         if (key == null) {
             return;
@@ -1148,6 +1193,10 @@ public final class PointerTracker implements PointerTrackerQueue.Element,
             // We use longer timeout for sliding finger input started from the modifier key.
             return longpressTimeout * MULTIPLIER_FOR_LONG_PRESS_TIMEOUT_IN_SLIDING_INPUT;
         }
+        if (code == Constants.CODE_SPACE) {
+            // Cursor can be moved in space
+            return longpressTimeout * MULTIPLIER_FOR_LONG_PRESS_TIMEOUT_IN_SLIDING_INPUT;
+        }
         return longpressTimeout;
     }
 

app/src/main/java/org/dslul/openboard/inputmethod/latin/LatinIME.java

@@ -40,6 +40,7 @@ import android.os.IBinder;
 import android.os.Message;
 import android.preference.PreferenceManager;
 import android.text.InputType;
+import android.text.TextUtils;
 import android.util.Log;
 import android.util.PrintWriterPrinter;
 import android.util.Printer;
@@ -1357,6 +1358,38 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         return false;
     }
 
+    @Override
+    public void onMovePointer(int steps) {
+        if (steps < 0) {
+            int availableCharacters = getCurrentInputConnection().getTextBeforeCursor(64, 0).length();
+            steps = availableCharacters < -steps ? -availableCharacters : steps;
+        }
+        else if (steps > 0) {
+            int availableCharacters = getCurrentInputConnection().getTextAfterCursor(64, 0).length();
+            steps = availableCharacters < steps ? availableCharacters : steps;
+        } else return;
+
+        int newPosition = mInputLogic.mConnection.mExpectedSelStart + steps;
+        getCurrentInputConnection().setSelection(newPosition, newPosition);
+    }
+
+    @Override
+    public void onMoveDeletePointer(int steps) {
+        int end = mInputLogic.mConnection.getExpectedSelectionEnd();
+        int start = mInputLogic.mConnection.getExpectedSelectionStart() + steps;
+        if (start > end)
+            return;
+        mInputLogic.mConnection.setSelection(start, end);
+    }
+
+    @Override
+    public void onUpWithDeletePointerActive() {
+        if (mInputLogic.mConnection.hasSelection()) {
+            mInputLogic.sendDownUpKeyEvent(KeyEvent.KEYCODE_DEL);
+            mInputLogic.finishInput();
+        }
+    }
+
     private boolean isShowingOptionDialog() {
         return mOptionsDialog != null && mOptionsDialog.isShowing();
     }

app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputConnection.java

@@ -103,12 +103,12 @@ public final class RichInputConnection implements PrivateCommandPerformer {
      * It's not really the selection start position: the selection start may not be there yet, and
      * in some cases, it may never arrive there.
      */
-    private int mExpectedSelStart = INVALID_CURSOR_POSITION; // in chars, not code points
+    public int mExpectedSelStart = INVALID_CURSOR_POSITION; // in chars, not code points
     /**
      * The expected selection end.  Only differs from mExpectedSelStart if a non-empty selection is
      * expected.  The same caveats as mExpectedSelStart apply.
      */
-    private int mExpectedSelEnd = INVALID_CURSOR_POSITION; // in chars, not code points
+    public int mExpectedSelEnd = INVALID_CURSOR_POSITION; // in chars, not code points
     /**
      * This contains the committed text immediately preceding the cursor and the composing
      * text, if any. It is refreshed when the cursor moves by calling upon the TextView.

app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java

@@ -1969,7 +1969,7 @@ public final class InputLogic {
      *
      * @param keyCode the key code to send inside the key event.
      */
-    private void sendDownUpKeyEvent(final int keyCode) {
+    public void sendDownUpKeyEvent(final int keyCode) {
         final long eventTime = SystemClock.uptimeMillis();
         mConnection.sendKeyEvent(new KeyEvent(eventTime, eventTime,
                 KeyEvent.ACTION_DOWN, keyCode, 0, 0, KeyCharacterMap.VIRTUAL_KEYBOARD, 0,

app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/Settings.java

@@ -83,6 +83,8 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     public static final String PREF_CUSTOM_INPUT_STYLES = "custom_input_styles";
     public static final String PREF_ENABLE_SPLIT_KEYBOARD = "pref_split_keyboard";
     public static final String PREF_KEYBOARD_HEIGHT_SCALE = "pref_keyboard_height_scale";
+    public static final String PREF_SPACE_TRACKPAD = "pref_space_trackpad";
+    public static final String PREF_DELETE_SWIPE = "pref_delete_swipe";
     // TODO: consolidate key preview dismiss delay with the key preview animation parameters.
     public static final String PREF_KEY_PREVIEW_POPUP_DISMISS_DELAY =
             "pref_key_preview_popup_dismiss_delay";
@@ -354,6 +356,14 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
         return (percentage != UNDEFINED_PREFERENCE_VALUE_FLOAT) ? percentage : defaultValue;
     }
 
+    public static boolean readSpaceTrackpadEnabled(final SharedPreferences prefs) {
+        return prefs.getBoolean(PREF_SPACE_TRACKPAD, true);
+    }
+
+    public static boolean readDeleteSwipeEnabled(final SharedPreferences prefs) {
+        return prefs.getBoolean(PREF_DELETE_SWIPE, true);
+    }
+
     public static boolean readUseFullscreenMode(final Resources res) {
         return res.getBoolean(R.bool.config_use_fullscreen_mode);
     }

app/src/main/java/org/dslul/openboard/inputmethod/latin/settings/SettingsValues.java

@@ -73,6 +73,8 @@ public class SettingsValues {
     public final boolean mUsePersonalizedDicts;
     public final boolean mUseDoubleSpacePeriod;
     public final boolean mBlockPotentiallyOffensive;
+    public final boolean mSpaceTrackpadEnabled;
+    public final boolean mDeleteSwipeEnabled;
     // Use bigrams to predict the next word when there is no input for it yet
     public final boolean mBigramPredictionEnabled;
     public final boolean mGestureInputEnabled;
@@ -223,6 +225,8 @@ public class SettingsValues {
             new TargetPackageInfoGetterTask(context, mAppWorkarounds)
                     .execute(mInputAttributes.mTargetApplicationPackageName);
         }
+        mSpaceTrackpadEnabled = Settings.readSpaceTrackpadEnabled(prefs);
+        mDeleteSwipeEnabled = Settings.readDeleteSwipeEnabled(prefs);
     }
 
     public boolean isMetricsLoggingEnabled() {

app/src/main/res/values/strings.xml

@@ -597,4 +597,8 @@ Tip: You can download and remove dictionaries by going to <b>Languages &
          This resource is copied from packages/apps/Settings/res/values/strings.xml -->
     <!-- This resource is corresponding to msgid="5433275485499039199" -->
     <string name="user_dict_fast_scroll_alphabet">\u0020ABCDEFGHIJKLMNOPQRSTUVWXYZ</string>
+    <string name="delete_swipe">Delete swipe</string>
+    <string name="space_trackpad">Space bar trackpad</string>
+    <string name="delete_swipe_summary">Perform a swipe from the delete key to select and remove bigger portions of text at once</string>
+    <string name="space_trackpad_summary">Swipe on the spacebar to move the cursor</string>
 </resources>

app/src/main/res/xml/prefs_screen_advanced.xml

@@ -48,6 +48,16 @@
         android:title="@string/show_setup_wizard_icon"
         android:summary="@string/show_setup_wizard_icon_summary"
         android:persistent="true" />
+    <CheckBoxPreference
+        android:key="pref_space_trackpad"
+        android:title="@string/space_trackpad"
+        android:summary="@string/space_trackpad_summary"
+        android:defaultValue="true" />
+    <CheckBoxPreference
+        android:key="pref_delete_swipe"
+        android:title="@string/delete_swipe"
+        android:summary="@string/delete_swipe_summary"
+        android:defaultValue="true" />
     <PreferenceScreen
         android:fragment="org.dslul.openboard.inputmethod.latin.settings.DebugSettingsFragment"
         android:key="screen_debug"