Adding support for horizontal scrolling (touch pad and touch screen) (#…

…6154)

Also, adding support for devices which report fractional scrolling
amounts. E.g. a mouse with a continuous mouse wheel, or a Mac touch
pad. This is currently only supported in lwjgl3. It can probably be
added to android and maybe to gwt.

InputProcessor scrolled method now receives scroll amount for X and
Y. Changed type to float to support devices which report fractional
scroll amounts. Keeping the original scroll method of InputProcessor
for backward compatibility.  Updated InputEvent in scene2d
accordingly: added scrollAmountX, scrollAmountY attributes and
corresponding setters and getters.

Input event queue can receive float scrolling values.

Updated backends accordingly: lwjgl, lwjgl3, android and gwt.

Co-authored-by: Julien Pauty <julien@griottemail.com>
Co-authored-by: Benjamin Schulte <MrStahlfelge@users.noreply.github.com>

CHANGES

@@ -37,6 +37,7 @@
 - API Change: Enabling fullscreen mode on the lwjgl3 backend now automatically sets the vsync setting again.
 - API Addition: Added put(key, value, defaultValue) for maps with primitive keys, so the old value can be returned.
 - API Addition: Added ObjectLongMap.
+- API Change: InputProcessor scrolled method now receives scroll amount for X and Y. Changed type to float to support devices which report fractional scroll amounts. Updated InputEvent in scene2d accordingly: added scrollAmountX, scrollAmountY attributes and corresponding setters and getters.
 - Added Intersector#intersectRayOrientedBoundsFast to detect if a ray intersects an oriented bounding box, see https://github.com/libgdx/libgdx/pull/6139
 - API Addition: Added Table#clip() and Container#clip() methods.
 - API Addition: Added getBackgroundDrawable() to Button.

backends/gdx-backend-android/src/com/badlogic/gdx/backends/android/AndroidMouseHandler.java

@@ -35,7 +35,8 @@ public boolean onGenericMotion (MotionEvent event, DefaultAndroidInput input) {
 		final int action = event.getAction() & MotionEvent.ACTION_MASK;
 
 		int x = 0, y = 0;
-		int scrollAmount = 0;
+		int scrollAmountX = 0;
+		int scrollAmountY = 0;
 
 		long timeStamp = System.nanoTime();
 		synchronized (input) {
@@ -44,15 +45,16 @@ public boolean onGenericMotion (MotionEvent event, DefaultAndroidInput input) {
 				x = (int)event.getX();
 				y = (int)event.getY();
 				if ((x != deltaX) || (y != deltaY)) { // Avoid garbage events
-					postTouchEvent(input, TouchEvent.TOUCH_MOVED, x, y, 0, timeStamp);
+					postTouchEvent(input, TouchEvent.TOUCH_MOVED, x, y, 0, 0, timeStamp);
 					deltaX = x;
 					deltaY = y;
 				}
 				break;
 
 			case MotionEvent.ACTION_SCROLL:
-				scrollAmount = (int)-Math.signum(event.getAxisValue(MotionEvent.AXIS_VSCROLL));
-				postTouchEvent(input, TouchEvent.TOUCH_SCROLLED, 0, 0, scrollAmount, timeStamp);
+				scrollAmountY = (int)-Math.signum(event.getAxisValue(MotionEvent.AXIS_VSCROLL));
+				scrollAmountX = (int)-Math.signum(event.getAxisValue(MotionEvent.AXIS_HSCROLL));
+				postTouchEvent(input, TouchEvent.TOUCH_SCROLLED, 0, 0, scrollAmountX, scrollAmountY, timeStamp);
 
 			}
 		}
@@ -75,13 +77,14 @@ else if (action == MotionEvent.ACTION_SCROLL)
 		Gdx.app.log("AndroidMouseHandler", "action " + actionStr);
 	}
 
-	private void postTouchEvent (DefaultAndroidInput input, int type, int x, int y, int scrollAmount, long timeStamp) {
+	private void postTouchEvent (DefaultAndroidInput input, int type, int x, int y, int scrollAmountX, int scrollAmountY, long timeStamp) {
 		TouchEvent event = input.usedTouchEvents.obtain();
 		event.timeStamp = timeStamp;
 		event.x = x;
 		event.y = y;
 		event.type = type;
-		event.scrollAmount = scrollAmount;
+		event.scrollAmountX = scrollAmountX;
+		event.scrollAmountY = scrollAmountY;
 		input.touchEvents.add(event);
 	}
 

backends/gdx-backend-android/src/com/badlogic/gdx/backends/android/DefaultAndroidInput.java

@@ -77,7 +77,8 @@ static class TouchEvent {
 		int type;
 		int x;
 		int y;
-		int scrollAmount;
+		int scrollAmountX;
+		int scrollAmountY;
 		int button;
 		int pointer;
 	}
@@ -419,7 +420,7 @@ public void processEvents () {
 						processor.mouseMoved(e.x, e.y);
 						break;
 					case TouchEvent.TOUCH_SCROLLED:
-						processor.scrolled(e.scrollAmount);
+						processor.scrolled(e.scrollAmountX, e.scrollAmountY);
 					}
 					usedTouchEvents.free(e);
 				}

backends/gdx-backend-lwjgl/src/com/badlogic/gdx/backends/lwjgl/DefaultLwjglInput.java

@@ -367,7 +367,7 @@ public void processEvents () {
 						processor.mouseMoved(e.x, e.y);
 						break;
 					case TouchEvent.TOUCH_SCROLLED:
-						processor.scrolled(e.scrollAmount);
+						processor.scrolled(0, e.scrollAmount);
 					}
 					usedTouchEvents.free(e);
 				}

backends/gdx-backend-lwjgl/src/com/badlogic/gdx/backends/lwjgl/LwjglAWTInput.java

@@ -383,7 +383,7 @@ void processEvents () {
 						processor.mouseMoved(e.x, e.y);
 						break;
 					case TouchEvent.TOUCH_SCROLLED:
-						processor.scrolled(e.scrollAmount);
+						processor.scrolled(0, e.scrollAmount);
 						break;
 					}
 					usedTouchEvents.free(e);

backends/gdx-backend-lwjgl3/src/com/badlogic/gdx/backends/lwjgl3/DefaultLwjgl3Input.java

@@ -87,31 +87,10 @@ public void invoke(long window, int codepoint) {
 	};
 
 	private GLFWScrollCallback scrollCallback = new GLFWScrollCallback() {
-		private long pauseTime = 250000000L; //250ms
-		private float scrollYRemainder;
-		private long lastScrollEventTime;
 		@Override
 		public void invoke(long window, double scrollX, double scrollY) {
 			DefaultLwjgl3Input.this.window.getGraphics().requestRendering();
-			if (scrollYRemainder > 0 && scrollY < 0 || scrollYRemainder < 0 && scrollY > 0 ||
-				TimeUtils.nanoTime() - lastScrollEventTime > pauseTime ) { 
-				// fire a scroll event immediately:
-				//  - if the scroll direction changes; 
-				//  - if the user did not move the wheel for more than 250ms
-				scrollYRemainder = 0;
-				int scrollAmount = (int)-Math.signum(scrollY);
-				eventQueue.scrolled(scrollAmount);
-				lastScrollEventTime = TimeUtils.nanoTime();
-			}
-			else {
-				scrollYRemainder += scrollY;
-				while (Math.abs(scrollYRemainder) >= 1) {
-					int scrollAmount = (int)-Math.signum(scrollY);
-					eventQueue.scrolled(scrollAmount);
-					lastScrollEventTime = TimeUtils.nanoTime();
-					scrollYRemainder += scrollAmount;
-				}
-			}
+			eventQueue.scrolled(-(float)scrollX, -(float)scrollY);
 		}
 	};
 

backends/gdx-backends-gwt/src/com/badlogic/gdx/backends/gwt/DefaultGwtInput.java

@@ -715,7 +715,7 @@ private void handleEvent (NativeEvent e) {
 		}
 		if (e.getType().equals(getMouseWheelEvent())) {
 			if (processor != null) {
-				processor.scrolled((int)getMouseWheelVelocity(e));
+				processor.scrolled(0, (int)getMouseWheelVelocity(e));
 			}
 			this.currentEventTimeStamp = TimeUtils.nanoTime();
 			e.preventDefault();

extensions/gdx-tools/src/com/badlogic/gdx/tools/particleeditor/ParticleEditor.java

@@ -350,11 +350,11 @@ public OrthoCamController (OrthographicCamera camera) {
 			}
 
 			@Override
-			public boolean scrolled (int amount) {
-				worldCamera.zoom += amount * 0.01f;
+			public boolean scrolled (float amountX, float amountY) {
+				worldCamera.zoom += amountY * 0.01f;
 				worldCamera.zoom = MathUtils.clamp(worldCamera.zoom, 0.01f, 5000);
 				worldCamera.update();
-				return super.scrolled(amount);
+				return super.scrolled(amountX, amountY);
 			}
 
 			@Override
@@ -599,7 +599,7 @@ public boolean mouseMoved (int x, int y) {
 		}
 
 		@Override
-		public boolean scrolled (int amount) {
+		public boolean scrolled (float amountX, float amountY) {
 			return false;
 		}
 

gdx/src/com/badlogic/gdx/InputAdapter.java

@@ -50,7 +50,7 @@ public boolean mouseMoved (int screenX, int screenY) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
+	public boolean scrolled (float amountX, float amountY) {
 		return false;
 	}
 }

gdx/src/com/badlogic/gdx/InputEventQueue.java

@@ -18,6 +18,7 @@
 
 import com.badlogic.gdx.utils.IntArray;
 import com.badlogic.gdx.utils.TimeUtils;
+import com.badlogic.gdx.utils.NumberUtils;
 
 /** Queues events that are later passed to the wrapped {@link InputProcessor}.
  * @author Nathan Sweet */
@@ -92,7 +93,7 @@ public void drain () {
 				localProcessor.mouseMoved(q[i++], q[i++]);
 				break;
 			case SCROLLED:
-				localProcessor.scrolled(q[i++]);
+				localProcessor.scrolled(NumberUtils.intBitsToFloat(q[i++]) , NumberUtils.intBitsToFloat(q[i++]));
 				break;
 			default:
 				throw new RuntimeException();
@@ -133,7 +134,7 @@ private synchronized int next (int nextType, int i) {
 				i += 2;
 				break;
 			case SCROLLED:
-				i++;
+				i += 2;
 				break;
 			default:
 				throw new RuntimeException();
@@ -218,10 +219,11 @@ public synchronized boolean mouseMoved (int screenX, int screenY) {
 		return false;
 	}
 
-	public synchronized boolean scrolled (int amount) {
+	public synchronized boolean scrolled(float amountX, float amountY) {
 		queue.add(SCROLLED);
 		queueTime();
-		queue.add(amount);
+		queue.add(NumberUtils.floatToIntBits(amountX));
+		queue.add(NumberUtils.floatToIntBits(amountY));
 		return false;
 	}
 

gdx/src/com/badlogic/gdx/InputMultiplexer.java

@@ -150,11 +150,11 @@ public boolean mouseMoved (int screenX, int screenY) {
 		return false;
 	}
 
-	public boolean scrolled (int amount) {
+	public boolean scrolled (float amountX, float amountY) {
 		Object[] items = processors.begin();
 		try {
 			for (int i = 0, n = processors.size; i < n; i++)
-				if (((InputProcessor)items[i]).scrolled(amount)) return true;
+				if (((InputProcessor)items[i]).scrolled(amountX, amountY)) return true;
 		} finally {
 			processors.end();
 		}

gdx/src/com/badlogic/gdx/InputProcessor.java

@@ -67,7 +67,8 @@ public interface InputProcessor {
 	public boolean mouseMoved (int screenX, int screenY);
 
 	/** Called when the mouse wheel was scrolled. Will not be called on iOS.
-	 * @param amount the scroll amount, -1 or 1 depending on the direction the wheel was scrolled.
+	 * @param amountX the horizontal scroll amount, negative or positive depending on the direction the wheel was scrolled.
+	 * @param amountY the vertical scroll amount, negative or positive depending on the direction the wheel was scrolled.
 	 * @return whether the input was processed. */
-	public boolean scrolled (int amount);
+	public boolean scrolled (float amountX, float amountY);
 }

gdx/src/com/badlogic/gdx/graphics/g3d/utils/CameraInputController.java

@@ -203,8 +203,8 @@ public boolean touchDragged (int screenX, int screenY, int pointer) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
-		return zoom(amount * scrollFactor * translateUnits);
+	public boolean scrolled (float amountX, float amountY) {
+		return zoom(amountY * scrollFactor * translateUnits);
 	}
 
 	public boolean zoom (float amount) {

gdx/src/com/badlogic/gdx/input/RemoteSender.java

@@ -198,7 +198,7 @@ public boolean mouseMoved (int x, int y) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
+	public boolean scrolled (float amountX, float amountY) {
 		return false;
 	}
 

gdx/src/com/badlogic/gdx/scenes/scene2d/InputEvent.java

@@ -24,8 +24,8 @@
  * @see InputListener */
 public class InputEvent extends Event {
 	private Type type;
-	private float stageX, stageY;
-	private int pointer, button, keyCode, scrollAmount;
+	private float stageX, stageY, scrollAmountX, scrollAmountY;
+	private int pointer, button, keyCode;
 	private char character;
 	private @Null Actor relatedActor;
 	private boolean touchFocus = true;
@@ -103,13 +103,21 @@ public void setCharacter (char character) {
 		this.character = character;
 	}
 
-	/** The amount the mouse was scrolled. Valid for: scrolled. */
-	public int getScrollAmount () {
-		return scrollAmount;
+	/** The amount the mouse was scrolled horizontally. Valid for: scrolled. */
+	public float getScrollAmountX () {
+		return scrollAmountX;
+	}
+	/** The amount the mouse was scrolled vertically. Valid for: scrolled. */
+	public float getScrollAmountY () {
+		return scrollAmountY;
+	}
+
+	public void setScrollAmountX (float scrollAmount) {
+		this.scrollAmountX = scrollAmount;
 	}
 
-	public void setScrollAmount (int scrollAmount) {
-		this.scrollAmount = scrollAmount;
+	public void setScrollAmountY (float scrollAmount) {
+		this.scrollAmountY = scrollAmount;
 	}
 
 	/** The actor related to the event. Valid for: enter and exit. For enter, this is the actor being exited, or null. For exit,

gdx/src/com/badlogic/gdx/scenes/scene2d/InputListener.java

@@ -76,7 +76,7 @@ public boolean handle (Event e) {
 		case mouseMoved:
 			return mouseMoved(event, tmpCoords.x, tmpCoords.y);
 		case scrolled:
-			return scrolled(event, tmpCoords.x, tmpCoords.y, event.getScrollAmount());
+			return scrolled(event, tmpCoords.x, tmpCoords.y, event.getScrollAmountX(), event.getScrollAmountY());
 		case enter:
 			enter(event, tmpCoords.x, tmpCoords.y, event.getPointer(), event.getRelatedActor());
 			return false;
@@ -130,7 +130,7 @@ public void exit (InputEvent event, float x, float y, int pointer, @Null Actor t
 	}
 
 	/** Called when the mouse wheel has been scrolled. When true is returned, the event is {@link Event#handle() handled}. */
-	public boolean scrolled (InputEvent event, float x, float y, int amount) {
+	public boolean scrolled (InputEvent event, float x, float y, float amountX, float amountY) {
 		return false;
 	}
 

gdx/src/com/badlogic/gdx/scenes/scene2d/Stage.java

@@ -389,15 +389,16 @@ public boolean mouseMoved (int screenX, int screenY) {
 
 	/** Applies a mouse scroll event to the stage and returns true if an actor in the scene {@link Event#handle() handled} the
 	 * event. This event only occurs on the desktop. */
-	public boolean scrolled (int amount) {
+	public boolean scrolled (float amountX, float amountY) {
 		Actor target = scrollFocus == null ? root : scrollFocus;
 
 		screenToStageCoordinates(tempCoords.set(mouseScreenX, mouseScreenY));
 
 		InputEvent event = Pools.obtain(InputEvent.class);
 		event.setStage(this);
 		event.setType(InputEvent.Type.scrolled);
-		event.setScrollAmount(amount);
+		event.setScrollAmountX(amountX);
+		event.setScrollAmountY(amountY);
 		event.setStageX(tempCoords.x);
 		event.setStageY(tempCoords.y);
 		target.fire(event);

gdx/src/com/badlogic/gdx/scenes/scene2d/ui/ScrollPane.java

@@ -208,13 +208,12 @@ public boolean handle (Event event) {
 		addListener(flickScrollListener);
 
 		addListener(new InputListener() {
-			public boolean scrolled (InputEvent event, float x, float y, int amount) {
+			public boolean scrolled (InputEvent event, float x, float y, float scrollAmountX, float scrollAmountY) {
 				setScrollbarsVisible(true);
-				if (scrollY)
-					setScrollY(amountY + getMouseWheelY() * amount);
-				else if (scrollX) //
-					setScrollX(amountX + getMouseWheelX() * amount);
-				else
+				if (scrollY || scrollX) {
+					setScrollY(amountY + getMouseWheelY() * scrollAmountY);
+					setScrollX(amountX + getMouseWheelX() * scrollAmountX);
+				} else
 					return false;
 				return true;
 			}

tests/gdx-tests/src/com/badlogic/gdx/tests/Box2DTestCollection.java

@@ -121,7 +121,7 @@ public boolean mouseMoved (int x, int y) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
+	public boolean scrolled (float amountX, float amountY) {
 		return false;
 	}
 

tests/gdx-tests/src/com/badlogic/gdx/tests/BulletTestCollection.java

@@ -162,8 +162,8 @@ public boolean mouseMoved (int x, int y) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
-		return tests[testIndex].scrolled(amount);
+	public boolean scrolled (float amountX, float amountY) {
+		return tests[testIndex].scrolled(amountX, amountY);
 	}
 
 	@Override

tests/gdx-tests/src/com/badlogic/gdx/tests/InputTest.java

@@ -109,8 +109,8 @@ public boolean mouseMoved (int x, int y) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
-		Gdx.app.log("Input Test", "scrolled: " + amount);
+	public boolean scrolled (float amountX, float amountY) {
+		Gdx.app.log("Input Test", "scrolled: " + amountY);
 		return false;
 	}
 

tests/gdx-tests/src/com/badlogic/gdx/tests/InterpolationTest.java

@@ -119,9 +119,9 @@ public void changed (ChangeEvent event, Actor actor) {
 		stage.addActor(table);
 
 		Gdx.input.setInputProcessor(new InputMultiplexer(new InputAdapter() {
-			public boolean scrolled (int amount) {
+			public boolean scrolled (float amountX, float amountY) {
 				if (!Gdx.input.isKeyPressed(Keys.CONTROL_LEFT)) return false;
-				duration -= amount / 15f;
+				duration -= amountY / 15f;
 				duration = MathUtils.clamp(duration, 0, Float.POSITIVE_INFINITY);
 				return true;
 			}

tests/gdx-tests/src/com/badlogic/gdx/tests/OnscreenKeyboardTest.java

@@ -93,7 +93,7 @@ public boolean mouseMoved (int x, int y) {
 	}
 
 	@Override
-	public boolean scrolled (int amount) {
+	public boolean scrolled (float amountX, float amountY) {
 		// TODO Auto-generated method stub
 		return false;
 	}