Scrolling with Touch Events

[Programminglinguist]

My activity already extends BaseGameActivity.

I'm not sure how I extend it to IOnSceneTouchListener also. Do I need a new file for that? I'm a bit confused.

[coder_t2]

My activity already extends BaseGameActivity.

I'm not sure how I extend it to IOnSceneTouchListener also. Do I need a new file for that? I'm a bit confused.

It should implement IOnSceneTouchListener. So

Extends BaseGameActivity implements IOnSceneTouchListener

Hope that helps

[drjava72]

I think you can do it in just two steps (scrolling IEntity on screen)

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. public class StartGame extends BaseGameActivity implements IScrollDetectorListener, IOnSceneTouchListener[syntax=""][/syntax]

Parsed in 0.029 seconds, using GeSHi 1.0.8.4

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. @Override
2.         public Scene onLoadScene() {
3.                 mScene = new Scene();
4.                
5.                 this.mScrollDetector = new SurfaceScrollDetector(this);        
6.                 this.mScrollDetector.setEnabled(true);
7.                 this.mScene.setOnSceneTouchListener(this);
8.                 this.mScene.setOnSceneTouchListenerBindingEnabled(true);
9.                

Parsed in 0.030 seconds, using GeSHi 1.0.8.4

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. @Override
2.         public void onScroll(ScrollDetector pScollDetector, TouchEvent pTouchEvent, float pDistanceX, float pDistanceY) {
3.                 this.mCamera.offsetCenter(-pDistanceX, -pDistanceY);           
4.         }
5.  
6.         @Override
7.         public boolean onSceneTouchEvent(Scene pScene, TouchEvent pSceneTouchEvent) {
8.                 this.mScrollDetector.onTouchEvent(pSceneTouchEvent);
9.                 return true;           
10.         }

Parsed in 0.034 seconds, using GeSHi 1.0.8.4

And you are done

[Alexander13]

Hi, everybody.

I'm absolutely new to andEngine, but I have experience in Android development. So, please help me to solve this little problem.

I have a big picture - 1024x768, so I have to scroll it. Also I must put some clickable areas on this picture and place animated objects.

I've already done scrolling picture, but problem is that if I start scrolling from a clickable area I got a "click" result, but not scrolling. I don't know how to differ click from scroll.

Here is my class:

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. public class AndEngineLayoutActivity extends LayoutGameActivity implements IOnSceneTouchListener {
2.        
3.     private static final int CAMERA_WIDTH = 1000;
4.     private static final int CAMERA_HEIGHT = 1000;
5.    
6.     private Camera mCamera;
7.     private Texture mTexture;
8.     private TextureRegion mHouseMapTextureRegion;
9.     private TextureRegion mWardrobeRoomRegion;
10.    
11.     private static boolean isMove = false;
12.  

Parsed in 0.036 seconds, using GeSHi 1.0.8.4

My onLoadScene:

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. public Scene onLoadScene() {
2.                 this.mEngine.registerUpdateHandler(new FPSLogger());
3.                
4.                 final Scene scene = new Scene();
5.  
6.         final Sprite face = new Sprite(0, 0, this.mHouseMapTextureRegion);
7.         final Sprite roomWardrobe = new Sprite(100,100,this.mRoomRegion){
8.                 @Override
9.                 public boolean onAreaTouched(final TouchEvent pSceneTouchEvent, final float pTouchAreaLocalX, final float pTouchAreaLocalY){
10.                         if (AndEngineLayoutActivity.isMove){
11.                                 return true;
12.                         }
13.                         Intent intent = new Intent(AndEngineLayoutActivity.this,Activity_Room.class);
14.                                 startActivity(intent);
15.                                 finish();
16.                                 overridePendingTransition(0, 0);
17.                         return true;
18.                 }
19.         };
20.        
21.         scene.attachChild(face);
22.         scene.attachChild(roomWardrobe);
23.         scene.registerTouchArea(roomWardrobe);
24.        
25.         scene.setOnSceneTouchListenerBindingEnabled(true);
26.         //scene.setTouchAreaBindingEnabled(true);
27.        
28.         scene.setOnSceneTouchListener(this);
29.         return scene;
30.         }
31.  

Parsed in 0.039 seconds, using GeSHi 1.0.8.4

And my onSceneTouchEvent. I use flag isMove to prevent event onAreaTouched if I during scrolling touch this area. This func is so long cause I don't want to scroll my image out of borders.

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1. public boolean onSceneTouchEvent(Scene pScene, TouchEvent pTouchEvent) {
2.  
3.         if(pTouchEvent.getAction() == MotionEvent.ACTION_DOWN)
4.         {
5.                 mTouchX = pTouchEvent.getMotionEvent().getX();
6.                 mTouchY = pTouchEvent.getMotionEvent().getY();
7.         }
8.         else if(pTouchEvent.getAction() == MotionEvent.ACTION_MOVE)
9.         {
10.                 AndEngineLayoutActivity.isMove = true;
11.                 float currentX = pTouchEvent.getMotionEvent().getX();
12.                 float currentY = pTouchEvent.getMotionEvent().getY();
13.                
14.                 mTouchOffsetX = (mTouchX - currentX);
15.                 mTouchOffsetY = (mTouchY - currentY);
16.                
17.                 int maxX = (int)((bitmap.getWidth() / 2) - (mCamera.getWidth()/2));
18.                 int maxY = (int)((bitmap.getHeight() /2 ) - (mCamera.getHeight() /2));
19.                 final float maxLeft = 0;
20.                 final float maxRight = maxX;
21.                 final float maxTop = maxY;
22.                 final float maxBottom = 0;
23.                
24.              // scrolling to left side of image (pic moving to the right)
25.                                 if (currentX > mTouchX)
26.                 {
27.                     if (totalX == maxLeft)
28.                         mTouchOffsetX = 0;
29.                     if (totalX > maxLeft)
30.                         totalX = totalX + mTouchOffsetX;
31.                     if (totalX < maxLeft){
32.                         mTouchOffsetX = maxLeft - (totalX - mTouchOffsetX);
33.                         totalX = maxLeft;
34.                     }
35.                 }
36.                 // scrolling to right side of image (pic moving to the left)
37.                 if (currentX < mTouchX)
38.                 {
39.                     if (totalX == maxRight)
40.                         mTouchOffsetX = 0;
41.                     if (totalX < maxRight)
42.                         totalX = totalX + mTouchOffsetX;
43.                     if (totalX > maxRight){
44.                         mTouchOffsetX = maxRight - (totalX - mTouchOffsetX);
45.                         totalX = maxRight;
46.                     }
47.                 }
48.                 // scrolling to top of image (pic moving to the bottom)
49.                 if (currentY > mTouchY)
50.                 {
51.                     if (totalY == maxTop)
52.                         mTouchOffsetY = 0;
53.                     if (totalY > maxTop)
54.                         totalY = totalY + mTouchOffsetY;
55.                     if (totalY < maxTop){
56.                         mTouchOffsetY = maxTop - (totalY - mTouchOffsetY);
57.                         totalY = maxTop;
58.                     }
59.                 }
60.                 // scrolling to bottom of image (pic moving to the top)
61.                 if (currentY < mTouchY)
62.                 {
63.                     if (totalY == maxBottom)
64.                         mTouchOffsetY = 0;
65.                     if (totalY < maxBottom)
66.                         totalY = totalY + mTouchOffsetY;
67.                     if (totalY > maxBottom){
68.                         mTouchOffsetY = maxBottom - (totalY - mTouchOffsetY);
69.                         totalY = maxBottom;
70.                     }
71.                 }
72.  
73.                 float newScrollX = this.mCamera.getCenterX() - mTouchOffsetX;
74.                 float newScrollY = this.mCamera.getCenterY() - mTouchOffsetY;
75.                
76.                 this.mCamera.setCenter(newScrollX, newScrollY);
77.                
78.                 mTouchX = currentX;
79.                 mTouchY = currentY;
80.         }
81.                 if(pTouchEvent.getAction() == MotionEvent.ACTION_UP){
82.                 AndEngineLayoutActivity.isMove = false;
83.         }
84.         return true;
85. }
86.  

Parsed in 0.049 seconds, using GeSHi 1.0.8.4

If anybody knows how to help me solve my problem or to optimize this code, please help me. I read about ScrollDetector and TouchDetector, but I don't understand how to use it.

[vito]

Help me please!
I have a scene and I have a sprite on it. When I scrolling scene my sprite move with it to, but sprite must stay on the screen. How can I do it?
Sorry for my English, I am from Ukraine

[Pleerock]

Help me please!
I have a scene and I have a sprite on it. When I scrolling scene my sprite move with it to, but sprite must stay on the screen. How can I do it?
Sorry for my English, I am from Ukraine

Yeah, its a very actual problem. Can anyone help?

[zeljkoa]

Use HUD.

[bos]

I have a scene and I have a sprite on it. When I scrolling scene my sprite move with it to, but sprite must stay on the screen. How can I do it?

Untested: detach the parent-child-relationship when scrolling, and re-attach after scrolling. As long as there's a relationship, the sprite goes with the parent (scene).

[chetan.sonparote]

great Example!!

used it to make top down scroll list.

Please tell me how to set the limits of scrolling in y axis.
thanks

[vitors]

great Example!!

used it to make top down scroll list.

Please tell me how to set the limits of scrolling in y axis.
thanks

In PinchZoomExample i deleted the Zoom parts of the code and changed this:

Syntax: [ Download ] [ Hide ]

Syntax: [ Download ] [ Show ]

Using java Syntax Highlighting

1.         @Override
2.         public void onScrollStarted(final ScrollDetector pScollDetector, final int pPointerID, final float pDistanceX, final float pDistanceY) {
3.                 final float zoomFactor = this.mZoomCamera.getZoomFactor();
4.                 this.mZoomCamera.offsetCenter(-pDistanceX / zoomFactor, 0);
5.         }
6.  
7.         @Override
8.         public void onScroll(final ScrollDetector pScollDetector, final int pPointerID, final float pDistanceX, final float pDistanceY) {
9.                 final float zoomFactor = this.mZoomCamera.getZoomFactor();
10.                 this.mZoomCamera.offsetCenter(-pDistanceX / zoomFactor, 0);
11.         }
12.        
13.         @Override
14.         public void onScrollFinished(final ScrollDetector pScollDetector, final int pPointerID, final float pDistanceX, final float pDistanceY) {
15.                 final float zoomFactor = this.mZoomCamera.getZoomFactor();
16.                 this.mZoomCamera.offsetCenter(-pDistanceX / zoomFactor, 0);
17.         }
18.  

Parsed in 0.038 seconds, using GeSHi 1.0.8.4

And now the scroll only occur on x axis.