// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.ui.brightness;

/// Allows clients to request changes to the screen's color adjustment matrix.
/// This protocol should be implemented and served by the owner of screen presentation.
@discoverable
@available(added=16)
open protocol ColorAdjustment {
    /// Called to change the color adjustment to a discrete value.
    /// The server will send a response once the request has been serviced.
    /// A client can then use this response to determine when to make
    /// additional calls when limiting the amount of requests being sent.
    flexible SetDiscreteColorAdjustment(struct {
        color_adjustment ColorAdjustmentTable;
    }) -> ();
};

/// Handler implemented by the owner of the presentation.
/// The UI component that controls brightness and screen tint uses this protocol to request changes
/// to the screen's color adjustment matrix.
@discoverable
closed protocol ColorAdjustmentHandler {
    /// Called when the color adjustment  has changed.
    strict SetColorAdjustment(struct {
        color_adjustment ColorAdjustmentTable;
    });
};

/// The table for screen color tint adjustments.
type ColorAdjustmentTable = table {
    /// 3x3 Matrix in row-major form which will be used by root presenter
    /// to apply color adjustment.
    /// This field may be omitted to disable color adjustment.
    1: matrix array<float32, 9>;
};