Android: vertikale 3d listview

Question

Ich möchte vertikale 3D-Listenansicht like here machen, aber für ImageButtons und kostenlos. Gibt es dafür eine Bibliothek oder einen Beispielcode? Ich bin neu in der Android-Entwicklung, also weiß ich nicht, wie man so etwas animieren kann

Answer 1

ist eigentlich ziemlich einfach. Sie müssen ListView erweitern und onDrawChild() überschreiben. Dort können Sie 3D-Transformationsmatrizen anwenden, um den gewünschten Effekt zu erzielen. Ich habe ein funktionierendes Beispiel auf meinem github Oder Sie können einen Blick auf diese question werfen, die ziemlich ähnlich ist.

Für Ihre Bequemlichkeit ist meine Implementierung eines 3D-Listview:

public class ListView3d extends ListView { 

    /** Ambient light intensity */ 
    private static final int AMBIENT_LIGHT = 55; 
    /** Diffuse light intensity */ 
    private static final int DIFFUSE_LIGHT = 200; 
    /** Specular light intensity */ 
    private static final float SPECULAR_LIGHT = 70; 
    /** Shininess constant */ 
    private static final float SHININESS = 200; 
    /** The max intensity of the light */ 
    private static final int MAX_INTENSITY = 0xFF; 

    private final Camera mCamera = new Camera(); 
    private final Matrix mMatrix = new Matrix(); 
    /** Paint object to draw with */ 
    private Paint mPaint; 

    public ListView3d(Context context, AttributeSet attrs) { 
     super(context, attrs); 
    } 

    @Override 
    protected boolean drawChild(Canvas canvas, View child, long drawingTime) { 
     // get top left coordinates 
     final int top = child.getTop(); 
     final int left = child.getLeft(); 
     Bitmap bitmap = child.getDrawingCache(); 
     if (bitmap == null) { 
      child.setDrawingCacheEnabled(true); 
      child.buildDrawingCache(); 
      bitmap = child.getDrawingCache(); 
     } 

     final int centerY = child.getHeight()/2; 
     final int centerX = child.getWidth()/2; 
     final int radius = getHeight()/2; 
     final int absParentCenterY = getTop() + getHeight()/2; 
     final int absChildCenterY = child.getTop() + centerX; 
     final int distanceY = absParentCenterY - absChildCenterY; 
     final int absDistance = Math.min(radius, Math.abs(distanceY)); 

     final float translateZ = (float) Math.sqrt((radius * radius) - (absDistance * absDistance)); 

     double radians = Math.acos((float) absDistance/radius); 
     double degree = 90 - (180/Math.PI) * radians; 

     mCamera.save(); 
     mCamera.translate(0, 0, radius - translateZ); 
     mCamera.rotateX((float) degree); // remove this line.. 
     if (distanceY < 0) { 
      degree = 360 - degree; 
     } 
     mCamera.rotateY((float) degree); // and change this to rotateX() to get a 
              // wheel like effect 
     mCamera.getMatrix(mMatrix); 
     mCamera.restore(); 

     // create and initialize the paint object 
     if (mPaint == null) { 
      mPaint = new Paint(); 
      mPaint.setAntiAlias(true); 
      mPaint.setFilterBitmap(true); 
     } 
     //highlight elements in the middle 
     mPaint.setColorFilter(calculateLight((float) degree)); 

     mMatrix.preTranslate(-centerX, -centerY); 
     mMatrix.postTranslate(centerX, centerY); 
     mMatrix.postTranslate(left, top); 
     canvas.drawBitmap(bitmap, mMatrix, mPaint); 
     return false; 
    } 

    private LightingColorFilter calculateLight(final float rotation) { 
     final double cosRotation = Math.cos(Math.PI * rotation/180); 
     int intensity = AMBIENT_LIGHT + (int) (DIFFUSE_LIGHT * cosRotation); 
     int highlightIntensity = (int) (SPECULAR_LIGHT * Math.pow(cosRotation, SHININESS)); 
     if (intensity > MAX_INTENSITY) { 
      intensity = MAX_INTENSITY; 
     } 
     if (highlightIntensity > MAX_INTENSITY) { 
      highlightIntensity = MAX_INTENSITY; 
     } 
     final int light = Color.rgb(intensity, intensity, intensity); 
     final int highlight = Color.rgb(highlightIntensity, highlightIntensity, highlightIntensity); 
     return new LightingColorFilter(light, highlight); 
    } 
} 

Prost