AMessage.h revision e370bb62b89d2f2980f519392010ea08a24c558e 
1/*
2 * Copyright (C) 2010 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 A_MESSAGE_H_
18
19#define A_MESSAGE_H_
20
21#include <media/stagefright/foundation/ABase.h>
22#include <media/stagefright/foundation/ALooper.h>
23#include <utils/KeyedVector.h>
24#include <utils/RefBase.h>
25
26namespace android {
27
28struct ABuffer;
29struct AString;
30struct Parcel;
31
32struct AMessage : public RefBase {
33    AMessage(uint32_t what = 0, ALooper::handler_id target = 0);
34
35    static sp<AMessage> FromParcel(const Parcel &parcel);
36    void writeToParcel(Parcel *parcel) const;
37
38    void setWhat(uint32_t what);
39    uint32_t what() const;
40
41    void setTarget(ALooper::handler_id target);
42    ALooper::handler_id target() const;
43
44    void clear();
45
46    void setInt32(const char *name, int32_t value);
47    void setInt64(const char *name, int64_t value);
48    void setSize(const char *name, size_t value);
49    void setFloat(const char *name, float value);
50    void setDouble(const char *name, double value);
51    void setPointer(const char *name, void *value);
52    void setString(const char *name, const char *s, ssize_t len = -1);
53    void setObject(const char *name, const sp<RefBase> &obj);
54    void setBuffer(const char *name, const sp<ABuffer> &buffer);
55    void setMessage(const char *name, const sp<AMessage> &obj);
56
57    void setRect(
58            const char *name,
59            int32_t left, int32_t top, int32_t right, int32_t bottom);
60
61    bool findInt32(const char *name, int32_t *value) const;
62    bool findInt64(const char *name, int64_t *value) const;
63    bool findSize(const char *name, size_t *value) const;
64    bool findFloat(const char *name, float *value) const;
65    bool findDouble(const char *name, double *value) const;
66    bool findPointer(const char *name, void **value) const;
67    bool findString(const char *name, AString *value) const;
68    bool findObject(const char *name, sp<RefBase> *obj) const;
69    bool findBuffer(const char *name, sp<ABuffer> *buffer) const;
70    bool findMessage(const char *name, sp<AMessage> *obj) const;
71
72    bool findRect(
73            const char *name,
74            int32_t *left, int32_t *top, int32_t *right, int32_t *bottom) const;
75
76    void post(int64_t delayUs = 0);
77
78    // Posts the message to its target and waits for a response (or error)
79    // before returning.
80    status_t postAndAwaitResponse(sp<AMessage> *response);
81
82    // If this returns true, the sender of this message is synchronously
83    // awaiting a response, the "replyID" can be used to send the response
84    // via "postReply" below.
85    bool senderAwaitsResponse(uint32_t *replyID) const;
86
87    void postReply(uint32_t replyID);
88
89    // Performs a deep-copy of "this", contained messages are in turn "dup'ed".
90    // Warning: RefBase items, i.e. "objects" are _not_ copied but only have
91    // their refcount incremented.
92    sp<AMessage> dup() const;
93
94    AString debugString(int32_t indent = 0) const;
95
96    enum Type {
97        kTypeInt32,
98        kTypeInt64,
99        kTypeSize,
100        kTypeFloat,
101        kTypeDouble,
102        kTypePointer,
103        kTypeString,
104        kTypeObject,
105        kTypeMessage,
106        kTypeRect,
107        kTypeBuffer,
108    };
109
110    size_t countEntries() const;
111    const char *getEntryNameAt(size_t index, Type *type) const;
112
113protected:
114    virtual ~AMessage();
115
116private:
117    uint32_t mWhat;
118    ALooper::handler_id mTarget;
119
120    struct Rect {
121        int32_t mLeft, mTop, mRight, mBottom;
122    };
123
124    struct Item {
125        union {
126            int32_t int32Value;
127            int64_t int64Value;
128            size_t sizeValue;
129            float floatValue;
130            double doubleValue;
131            void *ptrValue;
132            RefBase *refValue;
133            AString *stringValue;
134            Rect rectValue;
135        } u;
136        const char *mName;
137        Type mType;
138    };
139
140    enum {
141        kMaxNumItems = 64
142    };
143    Item mItems[kMaxNumItems];
144    size_t mNumItems;
145
146    Item *allocateItem(const char *name);
147    void freeItem(Item *item);
148    const Item *findItem(const char *name, Type type) const;
149
150    void setObjectInternal(
151            const char *name, const sp<RefBase> &obj, Type type);
152
153    DISALLOW_EVIL_CONSTRUCTORS(AMessage);
154};
155
156}  // namespace android
157
158#endif  // A_MESSAGE_H_
159