improved the detection of horizontal swiping on the virtual keys, to reduce the accidental swipes when only pressing the key

app/src/main/java/io/github/sspanak/tt9/ime/MainViewHandler.java

@@ -14,6 +14,7 @@ import io.github.sspanak.tt9.ui.main.ResizableMainView;
  * Informational methods for the on-screen keyboard
  **/
 abstract public class MainViewHandler extends HotkeyHandler {
+	private int width = 0;
 	OrientationListener orientationListener;
 
 	@Override
@@ -21,11 +22,18 @@ abstract public class MainViewHandler extends HotkeyHandler {
 		super.onInit();
 
 		if (orientationListener == null) {
-			orientationListener = new OrientationListener(this, mainView::onOrientationChanged);
+			orientationListener = new OrientationListener(this, this::onOrientationChanged);
 			orientationListener.start();
 		}
 	}
 
+	private void onOrientationChanged() {
+		width = 0;
+		if (mainView != null) {
+			mainView.onOrientationChanged();
+		}
+	}
+
 	protected void cleanUp() {
 		if (mainView != null) {
 			mainView.removeListeners();
@@ -107,4 +115,12 @@ abstract public class MainViewHandler extends HotkeyHandler {
 	public SettingsStore getSettings() {
 		return settings;
 	}
+
+	public int getWidth() {
+		if (width == 0 && mainView != null && mainView.getView() != null) {
+			width = mainView.getView().getWidth();
+		}
+
+		return width;
+	}
 }

app/src/main/java/io/github/sspanak/tt9/preferences/settings/SettingsStore.java

@@ -21,6 +21,7 @@ public class SettingsStore extends SettingsUI {
 	public final static int RESIZE_THROTTLING_TIME = 60; // ms
 	public final static byte SLOW_QUERY_TIME = 50; // ms
 	public final static int SLOW_QUERY_TIMEOUT = 3000; // ms
+	public final static float SOFT_KEY_AMOUNT_OF_KEY_WIDTH_FOR_SWIPE = 0.75f; // amount of key width
 	public final static int SOFT_KEY_DOUBLE_CLICK_DELAY = 500; // ms
 	public final static int SOFT_KEY_REPEAT_DELAY = 40; // ms
 	public final static int SOFT_KEY_TITLE_MAX_CHARS = 5;

app/src/main/java/io/github/sspanak/tt9/ui/main/keys/SoftKeyBackspace.java

@@ -41,8 +41,8 @@ public class SoftKeyBackspace extends SwipeableKey {
 	 * moves their finger slightly and the key does not delete anything.
 	 */
 	@Override
-	protected float getSwipeXThreshold(Context context) {
+	protected float getSwipeXThreshold() {
-		return isFastDeleteOn() ? super.getSwipeXThreshold(context) : Integer.MAX_VALUE;
+		return isFastDeleteOn() ? super.getSwipeXThreshold() : Integer.MAX_VALUE;
 	}
 
 
@@ -50,7 +50,7 @@ public class SoftKeyBackspace extends SwipeableKey {
 	 * Disable vertical swiping for backspace key.
 	 */
 	@Override
-	protected float getSwipeYThreshold(Context context) {
+	protected float getSwipeYThreshold() {
 		return Integer.MAX_VALUE;
 	}
 

app/src/main/java/io/github/sspanak/tt9/ui/main/keys/SoftKeyLF4.java

@@ -18,10 +18,6 @@ public class SoftKeyLF4 extends SwipeableKey {
 		return tt9 != null && tt9.getSettings().getEnabledLanguageIds().size() > 1;
 	}
 
-	@Override
-	protected float getSwipeXThreshold(Context context) {
-		return super.getSwipeXThreshold(context) * 3;
-	}
 
 	@Override
 	protected void handleHold() {

app/src/main/java/io/github/sspanak/tt9/ui/main/keys/SoftKeySettings.java

@@ -25,8 +25,8 @@ public class SoftKeySettings extends SwipeableKey {
 
 	// this key does not support holding at the moment, so just prevent it
 	@Override protected float getHoldDurationThreshold() { return 1000; }
-	@Override protected float getSwipeXThreshold(Context context) { return context.getResources().getDimensionPixelSize(R.dimen.numpad_key_height) * 0.75f; }
+	@Override protected float getSwipeXThreshold() { return getResources().getDimensionPixelSize(R.dimen.numpad_key_height) * 0.75f; }
-	@Override protected float getSwipeYThreshold(Context context) { return context.getResources().getDimensionPixelSize(R.dimen.numpad_key_height) / 4.0f; }
+	@Override protected float getSwipeYThreshold() { return getResources().getDimensionPixelSize(R.dimen.numpad_key_height) / 4.0f; }
 
 	@Override
 	protected boolean handleRelease() {

app/src/main/java/io/github/sspanak/tt9/ui/main/keys/SwipeableKey.java

@@ -2,11 +2,13 @@ package io.github.sspanak.tt9.ui.main.keys;
 
 import android.content.Context;
 import android.util.AttributeSet;
+import android.util.TypedValue;
 import android.view.MotionEvent;
 import android.view.View;
 
 import io.github.sspanak.tt9.R;
 import io.github.sspanak.tt9.preferences.settings.SettingsStore;
+import io.github.sspanak.tt9.util.Logger;
 import io.github.sspanak.tt9.util.Timer;
 
 abstract public class SwipeableKey extends SoftKey {
@@ -32,32 +34,62 @@ abstract public class SwipeableKey extends SoftKey {
 
 	public SwipeableKey(Context context) {
 		super(context);
-		resetTimeThresholds(context);
 	}
 
 
 	public SwipeableKey(Context context, AttributeSet attrs) {
 		super(context, attrs);
-		resetTimeThresholds(context);
 	}
 
 
 	public SwipeableKey(Context context, AttributeSet attrs, int defStyleAttr) {
 		super(context, attrs, defStyleAttr);
-		resetTimeThresholds(context);
 	}
 
 
-	protected final void resetTimeThresholds(Context context) {
+	private void resetTimeThreshold() {
 		HOLD_DURATION_THRESHOLD = getHoldDurationThreshold();
-		SWIPE_X_THRESHOLD = getSwipeXThreshold(context);
+	}
-		SWIPE_Y_THRESHOLD = getSwipeYThreshold(context);
+
+
+	private void initSwipeThresholds() {
+		if (SWIPE_X_THRESHOLD == 0) {
+			SWIPE_X_THRESHOLD = getSwipeXThreshold();
+		}
+
+		if (SWIPE_Y_THRESHOLD == 0) {
+			SWIPE_Y_THRESHOLD = getSwipeYThreshold();
+		}
 	}
 
 
 	protected float getHoldDurationThreshold() { return SettingsStore.SOFT_KEY_REPEAT_DELAY * 9; }
-	protected float getSwipeXThreshold(Context context) { return context.getResources().getDimensionPixelSize(R.dimen.numpad_key_height) / 10.0f; }
+	protected float getSwipeYThreshold() { return getResources().getDimensionPixelSize(R.dimen.numpad_key_height) / 10.0f; }
-	protected float getSwipeYThreshold(Context context) { return context.getResources().getDimensionPixelSize(R.dimen.numpad_key_height) / 10.0f; }
+
+
+	/**
+	 * Calculate the minimum amount of finger movement to be considered a swipe. It is meant
+	 * to prevent accidental swipes when pressing or holding the key.
+	 */
+	protected float getSwipeXThreshold() {
+		// If the key width is not available, use the old method. It's better than nothing.
+		if (tt9 == null || tt9.getWidth() == 0) {
+			return getSwipeYThreshold();
+		}
+
+		try {
+			// The simpler getResource.getFloat() requires API 29, so we must get the value manually.
+			TypedValue outValue = new TypedValue();
+			getResources().getValue(R.dimen.numpad_function_key_layout_weight, outValue, true);
+			float functionKeyScale = outValue.getFloat();
+
+			float keyWidth = tt9.getWidth() / 5f * functionKeyScale;
+			return keyWidth * SettingsStore.SOFT_KEY_AMOUNT_OF_KEY_WIDTH_FOR_SWIPE;
+		} catch (Exception e) {
+			Logger.e(LOG_TAG, "Error calculating the swipe X threshold. Using default to prevent crashing. " + e);
+			return getSwipeYThreshold();
+		}
+	}
 
 
 	private void updateSwipeTimingStats() {
@@ -85,6 +117,7 @@ abstract public class SwipeableKey extends SoftKey {
 		switch(event.getAction() & MotionEvent.ACTION_MASK) {
 			case MotionEvent.ACTION_DOWN:
 				Timer.start(LOG_TAG);
+				initSwipeThresholds();
 				onPress(event);
 				break;
 			case MotionEvent.ACTION_MOVE:
@@ -172,7 +205,7 @@ abstract public class SwipeableKey extends SoftKey {
 	@Override
 	public void render() {
 		// readjust the action detection delays for keys that set them dynamically
-		resetTimeThresholds(getContext());
+		resetTimeThreshold();
 		super.render();
 	}
 }