EdgeEffect

EdgeEffect

EdgeEffect(context: Context!)

Construct a new EdgeEffect with a theme appropriate for the provided context.

EdgeEffect

EdgeEffect(
    context: Context, 
    attrs: AttributeSet?)

Construct a new EdgeEffect with a theme appropriate for the provided context.

draw

open fun draw(canvas: Canvas!): Boolean

Draw into the provided canvas. Assumes that the canvas has been rotated accordingly and the size has been set. The effect will be drawn the full width of X=0 to X=width, beginning from Y=0 and extending to some factor < 1.f of height. The effect will only be visible on a hardware canvas, e.g. RenderNode#beginRecording().

finish

open fun finish(): Unit

Immediately finish the current animation. After this call isFinished() will return true.

getBlendMode

open fun getBlendMode(): BlendMode?

Returns the blend mode. A blend mode defines how source pixels (generated by a drawing command) are composited with the destination pixels (content of the render target).

getColor

open fun getColor(): Int

Return the color of this edge effect in argb.

getDistance

open fun getDistance(): Float

Returns the pull distance needed to be released to remove the showing effect. It is determined by the onPull(float,float) deltaDistance and any animating values, including from onAbsorb(int) and onRelease(). This can be used in conjunction with onPullDistance(float,float) to release the currently showing effect.

getMaxHeight

open fun getMaxHeight(): Int

Return the maximum height that the edge effect will be drawn at given the original input size.

isFinished

open fun isFinished(): Boolean

Reports if this EdgeEffect's animation is finished. If this method returns false after a call to draw(android.graphics.Canvas) the host widget should schedule another drawing pass to continue the animation.

onAbsorb

open fun onAbsorb(velocity: Int): Unit

Call when the effect absorbs an impact at the given velocity. Used when a fling reaches the scroll boundary.

When using a android.widget.Scroller or android.widget.OverScroller, the method getCurrVelocity will provide a reasonable approximation to use here.

onPull

open fun onPull(deltaDistance: Float): Unit

A view should call this when content is pulled away from an edge by the user. This will update the state of the current visual effect and its associated animation. The host view should always android.view.View#invalidate() after this and draw the results accordingly.

Views using EdgeEffect should favor onPull(float,float) when the displacement of the pull point is known.

onPull

open fun onPull(
    deltaDistance: Float, 
    displacement: Float
): Unit

A view should call this when content is pulled away from an edge by the user. This will update the state of the current visual effect and its associated animation. The host view should always android.view.View#invalidate() after this and draw the results accordingly.

onPullDistance

open fun onPullDistance(
    deltaDistance: Float, 
    displacement: Float
): Float

A view should call this when content is pulled away from an edge by the user. This will update the state of the current visual effect and its associated animation. The host view should always android.view.View#invalidate() after this and draw the results accordingly. This works similarly to onPull(float,float), but returns the amount of deltaDistance that has been consumed. If the getDistance() is currently 0 and deltaDistance is negative, this function will return 0 and the drawn value will remain unchanged. This method can be used to reverse the effect from a pull or absorb and partially consume some of a motion:

if (deltaY < 0) {
          float consumed = edgeEffect.onPullDistance(deltaY / getHeight(), x / getWidth());
          deltaY -= consumed * getHeight();
          if (edgeEffect.getDistance() == 0f) edgeEffect.onRelease();
      }
  

onRelease

open fun onRelease(): Unit

Call when the object is released after being pulled. This will begin the "decay" phase of the effect. After calling this method the host view should android.view.View#invalidate() and thereby draw the results accordingly.

setBlendMode

open fun setBlendMode(blendmode: BlendMode?): Unit

Set or clear the blend mode. A blend mode defines how source pixels (generated by a drawing command) are composited with the destination pixels (content of the render target).

setColor

open fun setColor(color: Int): Unit

Set the color of this edge effect in argb.

setSize

open fun setSize(
    width: Int, 
    height: Int
): Unit

Set the size of this edge effect in pixels.

DEFAULT_BLEND_MODE

static val DEFAULT_BLEND_MODE: BlendMode!

The default blend mode used by EdgeEffect.