New Pepper interfaces for audio/video capture device enumeration.

ppapi/api/dev/ppb_stream_device_enumerator_dev.idl

+/* Copyright (c) 2011 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**
+ * This file defines the <code>PPB_StreamDeviceEnumerator_Dev</code> interface.

[viettrungluu, 2011/12/17 01:37:03]

Ditto -- nothing stream-specific.

[yzshen1, 2011/12/19 19:11:55]

Done.

+ */
+label Chrome {
+  M18 = 0.1
+};
+
+interface PPB_StreamDeviceEnumerator_Dev {
+  /**
+   * This function creates a stream device enumerator resource.
+   *
+   * @param[in] instance A <code>PP_Instance</code> identifying one instance
+   * of a module.
+   *
+   * @return A <code>PP_Resource</code> containing the enumerator if successful
+   * or 0 if it could not be created.
+   */
+  PP_Resource Create([in] PP_Instance instance);
+
+  /**
+   * Determines if the provided resource is a stream device enumerator.
+   *
+   * @param[in] resource A <code>PP_Resource</code> corresponding to a generic
+   * resource.
+   *
+   * @return A <code>PP_Bool</code> that is <code>PP_TRUE</code> if the given
+   * resource is a stream device enumerator resource, otherwise
+   * <code>PP_FALSE</code>.
+   */
+  PP_Bool IsStreamDeviceEnumerator([in] PP_Resource resource);
+
+  /**
+   * Enumerates devices of the speicified stream type.
+   *
+   * @param[in] enumerator The stream device enumerator resource.
+   * @param[in] stream_type A <code>PP_StreamType_Dev</code> value describing
+   * what kind of devices is queried.
+   * @param[in] callback A <code>CompletionCallback</code> to be called when
+   * the operation is finished.
+   */
+  int32_t Enumerate(
+      [in] PP_Resource enumerator,
+      [in] PP_StreamType_Dev stream_type,
+      [in] PP_CompletionCallback callback);
+
+  /**
+   * Gets the number of devices found. It should be called after
+   * <code>Enumerate</code> completes successfully.
+   *
+   * @return The number of devices. If it is called before
+   * <code>Enumerate</code> is called or while it is being processed, it returns
+   * 0.
+   */
+  uint32_t GetDeviceNumber([in] PP_Resource enumerator);

[viettrungluu, 2011/12/17 01:37:03]

I wonder if this is overkill, and we shouldn't just have a "GetNextDevice()" (or
whatever), as in the file chooser.

(Or maybe the file chooser should be more like this.)

[yzshen1, 2011/12/19 19:11:55]

I think this may be easier for plugins. For example, it may want to reserve
resources in advance.

What do you think?

On 2011/12/17 01:37:03, viettrungluu wrote:

+
+  /**
+   * Gets a reference to a device. It should be called after
+   * <code>Enumerate</code> completes successfully.
+   *
+   * @param[in] enumerator The stream device enumerator resource.
+   * @param[in] index An integer indicating the position in the list of devices
+   * found.
+   *
+   * @return A <code>PP_Resource</code> indentifying the device.
+   * <code>PPB_AudioInput_Dev</code> and <code>PPB_VideoCapture_Dev</code> can
+   * use this reference to open the device. Returns 0 if the index is out of
+   * range.
+   */
+  PP_Resource GetDevice(
+      [in] PP_Resource enumerator,
+      [in] uint32_t index);
+};