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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef _UI_SPRITES_H
     18 #define _UI_SPRITES_H
     19 
     20 #include <utils/RefBase.h>
     21 #include <utils/Looper.h>
     22 
     23 #include <gui/SurfaceComposerClient.h>
     24 
     25 #include <SkBitmap.h>
     26 
     27 namespace android {
     28 
     29 /*
     30  * Transformation matrix for a sprite.
     31  */
     32 struct SpriteTransformationMatrix {
     33     inline SpriteTransformationMatrix() : dsdx(1.0f), dtdx(0.0f), dsdy(0.0f), dtdy(1.0f) { }
     34     inline SpriteTransformationMatrix(float dsdx, float dtdx, float dsdy, float dtdy) :
     35             dsdx(dsdx), dtdx(dtdx), dsdy(dsdy), dtdy(dtdy) { }
     36 
     37     float dsdx;
     38     float dtdx;
     39     float dsdy;
     40     float dtdy;
     41 
     42     inline bool operator== (const SpriteTransformationMatrix& other) {
     43         return dsdx == other.dsdx
     44                 && dtdx == other.dtdx
     45                 && dsdy == other.dsdy
     46                 && dtdy == other.dtdy;
     47     }
     48 
     49     inline bool operator!= (const SpriteTransformationMatrix& other) {
     50         return !(*this == other);
     51     }
     52 };
     53 
     54 /*
     55  * Icon that a sprite displays, including its hotspot.
     56  */
     57 struct SpriteIcon {
     58     inline SpriteIcon() : hotSpotX(0), hotSpotY(0) { }
     59     inline SpriteIcon(const SkBitmap& bitmap, float hotSpotX, float hotSpotY) :
     60             bitmap(bitmap), hotSpotX(hotSpotX), hotSpotY(hotSpotY) { }
     61 
     62     SkBitmap bitmap;
     63     float hotSpotX;
     64     float hotSpotY;
     65 
     66     inline SpriteIcon copy() const {
     67         SkBitmap bitmapCopy;
     68         bitmap.copyTo(&bitmapCopy, SkBitmap::kARGB_8888_Config);
     69         return SpriteIcon(bitmapCopy, hotSpotX, hotSpotY);
     70     }
     71 
     72     inline void reset() {
     73         bitmap.reset();
     74         hotSpotX = 0;
     75         hotSpotY = 0;
     76     }
     77 
     78     inline bool isValid() const {
     79         return !bitmap.isNull() && !bitmap.empty();
     80     }
     81 };
     82 
     83 /*
     84  * A sprite is a simple graphical object that is displayed on-screen above other layers.
     85  * The basic sprite class is an interface.
     86  * The implementation is provided by the sprite controller.
     87  */
     88 class Sprite : public RefBase {
     89 protected:
     90     Sprite() { }
     91     virtual ~Sprite() { }
     92 
     93 public:
     94     enum {
     95         // The base layer for pointer sprites.
     96         BASE_LAYER_POINTER = 0, // reserve space for 1 pointer
     97 
     98         // The base layer for spot sprites.
     99         BASE_LAYER_SPOT = 1, // reserve space for MAX_POINTER_ID spots
    100     };
    101 
    102     /* Sets the bitmap that is drawn by the sprite.
    103      * The sprite retains a copy of the bitmap for subsequent rendering. */
    104     virtual void setIcon(const SpriteIcon& icon) = 0;
    105 
    106     inline void clearIcon() {
    107         setIcon(SpriteIcon());
    108     }
    109 
    110     /* Sets whether the sprite is visible. */
    111     virtual void setVisible(bool visible) = 0;
    112 
    113     /* Sets the sprite position on screen, relative to the sprite's hot spot. */
    114     virtual void setPosition(float x, float y) = 0;
    115 
    116     /* Sets the layer of the sprite, relative to the system sprite overlay layer.
    117      * Layer 0 is the overlay layer, > 0 appear above this layer. */
    118     virtual void setLayer(int32_t layer) = 0;
    119 
    120     /* Sets the sprite alpha blend ratio between 0.0 and 1.0. */
    121     virtual void setAlpha(float alpha) = 0;
    122 
    123     /* Sets the sprite transformation matrix. */
    124     virtual void setTransformationMatrix(const SpriteTransformationMatrix& matrix) = 0;
    125 };
    126 
    127 /*
    128  * Displays sprites on the screen.
    129  *
    130  * This interface is used by PointerController and SpotController to draw pointers or
    131  * spot representations of fingers.  It is not intended for general purpose use
    132  * by other components.
    133  *
    134  * All sprite position updates and rendering is performed asynchronously.
    135  *
    136  * Clients are responsible for animating sprites by periodically updating their properties.
    137  */
    138 class SpriteController : public MessageHandler {
    139 protected:
    140     virtual ~SpriteController();
    141 
    142 public:
    143     SpriteController(const sp<Looper>& looper, int32_t overlayLayer);
    144 
    145     /* Creates a new sprite, initially invisible. */
    146     sp<Sprite> createSprite();
    147 
    148     /* Opens or closes a transaction to perform a batch of sprite updates as part of
    149      * a single operation such as setPosition and setAlpha.  It is not necessary to
    150      * open a transaction when updating a single property.
    151      * Calls to openTransaction() nest and must be matched by an equal number
    152      * of calls to closeTransaction(). */
    153     void openTransaction();
    154     void closeTransaction();
    155 
    156 private:
    157     enum {
    158         MSG_UPDATE_SPRITES,
    159         MSG_DISPOSE_SURFACES,
    160     };
    161 
    162     enum {
    163         DIRTY_BITMAP = 1 << 0,
    164         DIRTY_ALPHA = 1 << 1,
    165         DIRTY_POSITION = 1 << 2,
    166         DIRTY_TRANSFORMATION_MATRIX = 1 << 3,
    167         DIRTY_LAYER = 1 << 4,
    168         DIRTY_VISIBILITY = 1 << 5,
    169         DIRTY_HOTSPOT = 1 << 6,
    170     };
    171 
    172     /* Describes the state of a sprite.
    173      * This structure is designed so that it can be copied during updates so that
    174      * surfaces can be resized and redrawn without blocking the client by holding a lock
    175      * on the sprites for a long time.
    176      * Note that the SkBitmap holds a reference to a shared (and immutable) pixel ref. */
    177     struct SpriteState {
    178         inline SpriteState() :
    179                 dirty(0), visible(false),
    180                 positionX(0), positionY(0), layer(0), alpha(1.0f),
    181                 surfaceWidth(0), surfaceHeight(0), surfaceDrawn(false), surfaceVisible(false) {
    182         }
    183 
    184         uint32_t dirty;
    185 
    186         SpriteIcon icon;
    187         bool visible;
    188         float positionX;
    189         float positionY;
    190         int32_t layer;
    191         float alpha;
    192         SpriteTransformationMatrix transformationMatrix;
    193 
    194         sp<SurfaceControl> surfaceControl;
    195         int32_t surfaceWidth;
    196         int32_t surfaceHeight;
    197         bool surfaceDrawn;
    198         bool surfaceVisible;
    199 
    200         inline bool wantSurfaceVisible() const {
    201             return visible && alpha > 0.0f && icon.isValid();
    202         }
    203     };
    204 
    205     /* Client interface for a sprite.
    206      * Requests acquire a lock on the controller, update local state and request the
    207      * controller to invalidate the sprite.
    208      * The real heavy lifting of creating, resizing and redrawing surfaces happens
    209      * asynchronously with no locks held except in short critical section to copy
    210      * the sprite state before the work and update the sprite surface control afterwards.
    211      */
    212     class SpriteImpl : public Sprite {
    213     protected:
    214         virtual ~SpriteImpl();
    215 
    216     public:
    217         SpriteImpl(const sp<SpriteController> controller);
    218 
    219         virtual void setIcon(const SpriteIcon& icon);
    220         virtual void setVisible(bool visible);
    221         virtual void setPosition(float x, float y);
    222         virtual void setLayer(int32_t layer);
    223         virtual void setAlpha(float alpha);
    224         virtual void setTransformationMatrix(const SpriteTransformationMatrix& matrix);
    225 
    226         inline const SpriteState& getStateLocked() const {
    227             return mLocked.state;
    228         }
    229 
    230         inline void resetDirtyLocked() {
    231             mLocked.state.dirty = 0;
    232         }
    233 
    234         inline void setSurfaceLocked(const sp<SurfaceControl>& surfaceControl,
    235                 int32_t width, int32_t height, bool drawn, bool visible) {
    236             mLocked.state.surfaceControl = surfaceControl;
    237             mLocked.state.surfaceWidth = width;
    238             mLocked.state.surfaceHeight = height;
    239             mLocked.state.surfaceDrawn = drawn;
    240             mLocked.state.surfaceVisible = visible;
    241         }
    242 
    243     private:
    244         sp<SpriteController> mController;
    245 
    246         struct Locked {
    247             SpriteState state;
    248         } mLocked; // guarded by mController->mLock
    249 
    250         void invalidateLocked(uint32_t dirty);
    251     };
    252 
    253     /* Stores temporary information collected during the sprite update cycle. */
    254     struct SpriteUpdate {
    255         inline SpriteUpdate() : surfaceChanged(false) { }
    256         inline SpriteUpdate(const sp<SpriteImpl> sprite, const SpriteState& state) :
    257                 sprite(sprite), state(state), surfaceChanged(false) {
    258         }
    259 
    260         sp<SpriteImpl> sprite;
    261         SpriteState state;
    262         bool surfaceChanged;
    263     };
    264 
    265     mutable Mutex mLock;
    266 
    267     sp<Looper> mLooper;
    268     const int32_t mOverlayLayer;
    269     sp<WeakMessageHandler> mHandler;
    270 
    271     sp<SurfaceComposerClient> mSurfaceComposerClient;
    272 
    273     struct Locked {
    274         Vector<sp<SpriteImpl> > invalidatedSprites;
    275         Vector<sp<SurfaceControl> > disposedSurfaces;
    276         uint32_t transactionNestingCount;
    277         bool deferredSpriteUpdate;
    278     } mLocked; // guarded by mLock
    279 
    280     void invalidateSpriteLocked(const sp<SpriteImpl>& sprite);
    281     void disposeSurfaceLocked(const sp<SurfaceControl>& surfaceControl);
    282 
    283     void handleMessage(const Message& message);
    284     void doUpdateSprites();
    285     void doDisposeSurfaces();
    286 
    287     void ensureSurfaceComposerClient();
    288     sp<SurfaceControl> obtainSurface(int32_t width, int32_t height);
    289 };
    290 
    291 } // namespace android
    292 
    293 #endif // _UI_SPRITES_H
    294