Merge "Update view's alpha and layer docs" into jb-mr2-dev (94d6170b) · Commits · e / os / android_frameworks_base

core/java/android/view/View.java

+21 −17

Original line number	Diff line number	Diff line
		@@ -9485,17 +9485,26 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
		* <p>Sets the opacity of the view. This is a value from 0 to 1, where 0 means the view is
		* completely transparent and 1 means the view is completely opaque.</p>
		*
		* <p> Note that setting alpha to a translucent value (0 < alpha < 1) can have significant
		* performance implications, especially for large views. It is best to use the alpha property
		* sparingly and transiently, as in the case of fading animations.</p>
		*
		* <p>For a view with a frequently changing alpha, such as during a fading animation, it is
		* strongly recommended for performance reasons to either override
		* {@link #hasOverlappingRendering()} to return false if appropriate, or setting a
		* {@link #setLayerType(int, android.graphics.Paint) layer type} on the view.</p>
		*
		* <p>If this view overrides {@link #onSetAlpha(int)} to return true, then this view is
		* responsible for applying the opacity itself. Otherwise, calling this method is
		* equivalent to calling {@link #setLayerType(int, android.graphics.Paint)} and
		* setting a hardware layer.</p>
		* responsible for applying the opacity itself.</p>
		*
		* <p>Note that setting alpha to a translucent value (0 < alpha < 1) may have
		* performance implications. It is generally best to use the alpha property sparingly and
		* transiently, as in the case of fading animations.</p>
		* <p>Note that if the view is backed by a
		* {@link #setLayerType(int, android.graphics.Paint) layer} and is associated with a
		* {@link #setLayerPaint(android.graphics.Paint) layer paint}, setting an alpha value less than
		* 1.0 will supercede the alpha of the layer paint.</p>
		*
		* @param alpha The opacity of the view.
		*
		* @see #hasOverlappingRendering()
		* @see #setLayerType(int, android.graphics.Paint)
		*
		* @attr ref android.R.styleable#View_alpha
		@@ -12365,13 +12374,11 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
		* </ul>
		*
		* <p>If this view has an alpha value set to < 1.0 by calling
		* {@link #setAlpha(float)}, the alpha value of the layer's paint is replaced by
		* this view's alpha value. Calling {@link #setAlpha(float)} is therefore
		* equivalent to setting a hardware layer on this view and providing a paint with
		* the desired alpha value.</p>
		* {@link #setAlpha(float)}, the alpha value of the layer's paint is superceded
		* by this view's alpha value.</p>
		*
		* <p>Refer to the documentation of {@link #LAYER_TYPE_NONE disabled},
		* {@link #LAYER_TYPE_SOFTWARE software} and {@link #LAYER_TYPE_HARDWARE hardware}
		* <p>Refer to the documentation of {@link #LAYER_TYPE_NONE},
		* {@link #LAYER_TYPE_SOFTWARE} and {@link #LAYER_TYPE_HARDWARE}
		* for more information on when and how to use layers.</p>
		*
		* @param layerType The type of layer to use with this view, must be one of
		@@ -12441,11 +12448,8 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
		* <li>{@link android.graphics.Paint#getColorFilter() Color filter}</li>
		* </ul>
		*
		* <p>If this view has an alpha value set to < 1.0 by calling
		* {@link #setAlpha(float)}, the alpha value of the layer's paint is replaced by
		* this view's alpha value. Calling {@link #setAlpha(float)} is therefore
		* equivalent to setting a hardware layer on this view and providing a paint with
		* the desired alpha value.</p>
		* <p>If this view has an alpha value set to < 1.0 by calling {@link #setAlpha(float)}, the
		* alpha value of the layer's paint is superceded by this view's alpha value.</p>
		*
		* @param paint The paint used to compose the layer. This argument is optional
		* and can be null. It is ignored when the layer type is

libs/hwui/DisplayList.cpp

+7 −2

Original line number	Diff line number	Diff line
		@@ -352,7 +352,9 @@ void DisplayList::outputViewProperties(const int level) {
		}
		}
		if (mAlpha < 1) {
		if (mCaching \|\| !mHasOverlappingRendering) {
		if (mCaching) {
		ALOGD("%sSetOverrideLayerAlpha %.2f", level 2, "", mAlpha);
		} else if (!mHasOverlappingRendering) {
		ALOGD("%sScaleAlpha %.2f", level 2, "", mAlpha);
		} else {
		int flags = SkCanvas::kHasAlphaLayer_SaveFlag;
		@@ -400,7 +402,9 @@ void DisplayList::setViewProperties(OpenGLRenderer& renderer, T& handler,
		}
		}
		if (mAlpha < 1) {
		if (mCaching \|\| !mHasOverlappingRendering) {
		if (mCaching) {
		renderer.setOverrideLayerAlpha(mAlpha);
		} else if (!mHasOverlappingRendering) {
		renderer.scaleAlpha(mAlpha);
		} else {
		// TODO: should be able to store the size of a DL at record time and not
		@@ -513,6 +517,7 @@ void DisplayList::iterate(OpenGLRenderer& renderer, T& handler, const int level)
		DISPLAY_LIST_LOGD("%sRestoreToCount %d", (level + 1) 2, "", restoreTo);
		handler(mRestoreToCountOp->reinit(restoreTo), PROPERTY_SAVECOUNT);
		renderer.restoreToCount(restoreTo);
		renderer.setOverrideLayerAlpha(1.0f);
		}

		}; // namespace uirenderer

libs/hwui/OpenGLRenderer.cpp

+20 −5

Original line number	Diff line number	Diff line
		@@ -114,6 +114,7 @@ OpenGLRenderer::OpenGLRenderer():
		mCaches(Caches::getInstance()), mExtensions(Extensions::getInstance()) {
		mDrawModifiers.mShader = NULL;
		mDrawModifiers.mColorFilter = NULL;
		mDrawModifiers.mOverrideLayerAlpha = 1.0f;
		mDrawModifiers.mHasShadow = false;
		mDrawModifiers.mHasDrawFilter = false;

		@@ -1074,7 +1075,7 @@ void OpenGLRenderer::composeLayerRect(Layer* layer, const Rect& rect, bool swap)
		layer->setFilter(GL_LINEAR, true);
		}

		float alpha = layer->getAlpha() / 255.0f * mSnapshot->alpha;
		float alpha = getLayerAlpha(layer);
		bool blend = layer->isBlend() \|\| alpha < 1.0f;
		drawTextureMesh(x, y, x + rect.getWidth(), y + rect.getHeight(),
		layer->getTexture(), alpha, layer->getMode(), blend,
		@@ -1112,7 +1113,7 @@ void OpenGLRenderer::composeLayerRegion(Layer* layer, const Rect& rect) {
		rects = safeRegion.getArray(&count);
		}

		const float alpha = layer->getAlpha() / 255.0f * mSnapshot->alpha;
		const float alpha = getLayerAlpha(layer);
		const float texX = 1.0f / float(layer->getWidth());
		const float texY = 1.0f / float(layer->getHeight());
		const float height = rect.getHeight();
		@@ -2237,7 +2238,7 @@ status_t OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const
		float left, float top, float right, float bottom, SkPaint* paint) {
		int alpha;
		SkXfermode::Mode mode;
		getAlphaAndModeDirect(paint, &alpha, &mode);
		getAlphaAndMode(paint, &alpha, &mode);

		return drawPatch(bitmap, xDivs, yDivs, colors, width, height, numColors,
		left, top, right, bottom, alpha, mode);
		@@ -2990,7 +2991,7 @@ status_t OpenGLRenderer::drawLayer(Layer* layer, float x, float y) {
		if (layer->region.isRect()) {
		composeLayerRect(layer, layer->regionRect);
		} else if (layer->mesh) {
		const float a = layer->getAlpha() / 255.0f * mSnapshot->alpha;
		const float a = getLayerAlpha(layer);
		setupDraw();
		setupDrawWithTexture();
		setupDrawColor(a, a, a, a);
		@@ -3446,10 +3447,24 @@ void OpenGLRenderer::resetDrawTextureTexCoords(float u1, float v1, float u2, flo
		TextureVertex::setUV(v++, u2, v2);
		}

		void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) {
		void OpenGLRenderer::getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) const {
		getAlphaAndModeDirect(paint, alpha, mode);
		if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
		// if drawing a layer, ignore the paint's alpha
		*alpha = mDrawModifiers.mOverrideLayerAlpha;
		}
		alpha = mSnapshot->alpha;
		}

		float OpenGLRenderer::getLayerAlpha(Layer* layer) const {
		float alpha;
		if (mDrawModifiers.mOverrideLayerAlpha < 1.0f) {
		alpha = mDrawModifiers.mOverrideLayerAlpha;
		} else {
		alpha = layer->getAlpha() / 255.0f;
		}
		return alpha * mSnapshot->alpha;
		}

		}; // namespace uirenderer
		}; // namespace android

libs/hwui/OpenGLRenderer.h

+16 −4

Original line number	Diff line number	Diff line
		@@ -51,6 +51,7 @@ namespace uirenderer {
		struct DrawModifiers {
		SkiaShader* mShader;
		SkiaColorFilter* mColorFilter;
		float mOverrideLayerAlpha;

		// Drop shadow
		bool mHasShadow;
		@@ -275,6 +276,9 @@ public:
		virtual void resetPaintFilter();
		virtual void setupPaintFilter(int clearBits, int setBits);

		// If this value is set to < 1.0, it overrides alpha set on layer (see drawBitmap, drawLayer)
		void setOverrideLayerAlpha(float alpha) { mDrawModifiers.mOverrideLayerAlpha = alpha; }

		SkPaint* filterPaint(SkPaint* paint);

		bool storeDisplayState(DeferredDisplayState& state, int stateDeferFlags);
		@@ -283,7 +287,6 @@ public:
		const DrawModifiers& getDrawModifiers() { return mDrawModifiers; }
		void setDrawModifiers(const DrawModifiers& drawModifiers) { mDrawModifiers = drawModifiers; }

		// TODO: what does this mean? no perspective? no rotate?
		ANDROID_API bool isCurrentTransformSimple() {
		return mSnapshot->transform->isSimple();
		}
		@@ -325,7 +328,8 @@ public:
		/**
		* Gets the alpha and xfermode out of a paint object. If the paint is null
		* alpha will be 255 and the xfermode will be SRC_OVER. This method does
		* not multiply the paint's alpha by the current snapshot's alpha.
		* not multiply the paint's alpha by the current snapshot's alpha, and does
		* not replace the alpha with the overrideLayerAlpha
		*
		* @param paint The paint to extract values from
		* @param alpha Where to store the resulting alpha
		@@ -450,13 +454,21 @@ protected:

		/**
		* Gets the alpha and xfermode out of a paint object. If the paint is null
		* alpha will be 255 and the xfermode will be SRC_OVER.
		* alpha will be 255 and the xfermode will be SRC_OVER. Accounts for both
		* snapshot alpha, and overrideLayerAlpha
		*
		* @param paint The paint to extract values from
		* @param alpha Where to store the resulting alpha
		* @param mode Where to store the resulting xfermode
		*/
		inline void getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode);
		inline void getAlphaAndMode(SkPaint* paint, int* alpha, SkXfermode::Mode* mode) const;

		/**
		* Gets the alpha from a layer, accounting for snapshot alpha and overrideLayerAlpha
		*
		* @param layer The layer from which the alpha is extracted
		*/
		inline float getLayerAlpha(Layer* layer) const;

		/**
		* Safely retrieves the mode from the specified xfermode. If the specified