graphics/composer/2.1/IComposer.hal

/*
 * Copyright (C) 2016 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.
 */

package android.hardware.graphics.composer@2.1;

import IComposerClient;

interface IComposer {
    /**
     * Optional capabilities which may be supported by some devices. The
     * particular set of supported capabilities for a given device may be
     * retrieved using getCapabilities.
     */
    enum Capability : int32_t {
        INVALID = 0,

        /**
         * Specifies that the device supports sideband stream layers, for
         * which buffer content updates and other synchronization will not be
         * provided through the usual validate/present cycle and must be
         * handled by an external implementation-defined mechanism. Only
         * changes to layer state (such as position, size, etc.) need to be
         * performed through the validate/present cycle.
         */
        SIDEBAND_STREAM = 1,

        /**
         * Specifies that the device will apply a color transform even when
         * either the client or the device has chosen that all layers should
         * be composed by the client. This will prevent the client from
         * applying the color transform during its composition step.
         */
        SKIP_CLIENT_COLOR_TRANSFORM = 2,

        /**
         * Specifies that the present fence must not be used as an accurate
         * representation of the actual present time of a frame.
         */
        PRESENT_FENCE_IS_NOT_RELIABLE = 3,
    };

    /**
     * Provides a list of supported capabilities (as described in the
     * definition of Capability above). This list must not change after
     * initialization.
     *
     * @return capabilities is a list of supported capabilities.
     */
    @entry
    @exit
    @callflow(next="*")
    getCapabilities() generates (vec<Capability> capabilities);

    /**
     * Retrieves implementation-defined debug information, which will be
     * displayed during, for example, `dumpsys SurfaceFlinger`.
     *
     * @return debugInfo is a string of debug information.
     */
    @entry
    @exit
    @callflow(next="*")
    dumpDebugInfo() generates (string debugInfo);

    /**
     * Creates a client of the composer. All resources created by the client
     * are owned by the client and are only visible to the client.
     *
     * There can only be one client at any time.
     *
     * @return error is NONE upon success. Otherwise,
     *         NO_RESOURCES when no more client can be created currently.
     * @return client is the newly created client.
     */
    @entry
    @callflow(next="*")
    createClient() generates (Error error, IComposerClient client);
};