--- /dev/null
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef HW_EMULATOR_CAMERA_PREVIEW_WINDOW_H
+#define HW_EMULATOR_CAMERA_PREVIEW_WINDOW_H
+
+/*
+ * Contains declaration of a class PreviewWindow that encapsulates functionality
+ * of a preview window set via set_preview_window camera HAL API.
+ */
+
+namespace android {
+
+class EmulatedCameraDevice;
+
+/* Encapsulates functionality of a preview window set via set_preview_window
+ * camera HAL API.
+ *
+ * Objects of this class are contained in EmulatedCamera objects, and handle
+ * relevant camera API callbacks.
+ */
+class PreviewWindow {
+public:
+ /* Constructs PreviewWindow instance. */
+ PreviewWindow();
+
+ /* Destructs PreviewWindow instance. */
+ ~PreviewWindow();
+
+ /***************************************************************************
+ * Camera API
+ **************************************************************************/
+
+public:
+ /* Actual handler for camera_device_ops_t::set_preview_window callback.
+ * This method is called by the containing emulated camera object when it is
+ * handing the camera_device_ops_t::set_preview_window callback.
+ * Param:
+ * window - Preview window to set. This parameter might be NULL, which
+ * indicates preview window reset.
+ * preview_fps - Preview's frame frequency. This parameter determins when
+ * a frame received via onNextFrameAvailable call will be pushed to
+ * the preview window. If 'window' parameter passed to this method is
+ * NULL, this parameter is ignored.
+ * Return:
+ * NO_ERROR on success, or an appropriate error status.
+ */
+ status_t setPreviewWindow(struct preview_stream_ops* window,
+ int preview_fps);
+
+ /* Starts the preview.
+ * This method is called by the containing emulated camera object when it is
+ * handing the camera_device_ops_t::start_preview callback.
+ */
+ status_t startPreview();
+
+ /* Stops the preview.
+ * This method is called by the containing emulated camera object when it is
+ * handing the camera_device_ops_t::start_preview callback.
+ */
+ void stopPreview();
+
+ /* Checks if preview is enabled. */
+ inline bool isPreviewEnabled()
+ {
+ return mPreviewEnabled;
+ }
+
+ /****************************************************************************
+ * Public API
+ ***************************************************************************/
+
+public:
+ /* Next frame is available in the camera device.
+ * This is a notification callback that is invoked by the camera device when
+ * a new frame is available.
+ * Note that most likely this method is called in context of a worker thread
+ * that camera device has created for frame capturing.
+ * Param:
+ * frame - Captured frame, or NULL if camera device didn't pull the frame
+ * yet. If NULL is passed in this parameter use GetCurrentFrame method
+ * of the camera device class to obtain the next frame. Also note that
+ * the size of the frame that is passed here (as well as the frame
+ * returned from the GetCurrentFrame method) is defined by the current
+ * frame settings (width + height + pixel format) for the camera device.
+ * timestamp - Frame's timestamp.
+ * camera_dev - Camera device instance that delivered the frame.
+ */
+ void onNextFrameAvailable(const void* frame,
+ nsecs_t timestamp,
+ EmulatedCameraDevice* camera_dev);
+
+ /***************************************************************************
+ * Private API
+ **************************************************************************/
+
+protected:
+ /* Adjusts cached dimensions of the preview window frame according to the
+ * frame dimensions used by the camera device.
+ *
+ * When preview is started, it's not known (hard to define) what are going
+ * to be the dimensions of the frames that are going to be displayed. Plus,
+ * it might be possible, that such dimensions can be changed on the fly. So,
+ * in order to be always in sync with frame dimensions, this method is
+ * called for each frame passed to onNextFrameAvailable method, in order to
+ * properly adjust frame dimensions, used by the preview window.
+ * Note that this method must be called while object is locked.
+ * Param:
+ * camera_dev - Camera device, prpviding frames displayed in the preview
+ * window.
+ * Return:
+ * true if cached dimensions have been adjusted, or false if cached
+ * dimensions match device's frame dimensions.
+ */
+ bool adjustPreviewDimensions(EmulatedCameraDevice* camera_dev);
+
+ /* Checks if it's the time to push new frame to the preview window.
+ * Note that this method must be called while object is locked. */
+ bool isPreviewTime();
+
+ /***************************************************************************
+ * Data members
+ **************************************************************************/
+
+protected:
+ /* Locks this instance for data changes. */
+ Mutex mObjectLock;
+
+ /* Preview window instance. */
+ preview_stream_ops* mPreviewWindow;
+
+ /* Timestamp (abs. microseconds) when last frame has been pushed to the
+ * preview window. */
+ uint64_t mLastPreviewed;
+
+ /* Preview frequency in microseconds. */
+ uint32_t mPreviewAfter;
+
+ /*
+ * Cached preview window frame dimensions.
+ */
+
+ int mPreviewFrameWidth;
+ int mPreviewFrameHeight;
+
+ /* Preview status. */
+ bool mPreviewEnabled;
+};
+
+}; /* namespace android */
+
+#endif /* HW_EMULATOR_CAMERA_PREVIEW_WINDOW_H */
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