// Copyright 2017 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.policy;

using fuchsia.ui.gfx;
using fuchsia.ui.input;

// |Presentation.CaptureKeyboardEvent| will consume this listener interface and
// call |OnEvent| when the registered keyboard event occurs.
protocol KeyboardCaptureListenerHACK {
    OnEvent(fuchsia.ui.input.KeyboardEvent event);
};

// |Presentation.CapturePointerEvent| will consume this listener interface and
// call |OnEvent| when a pointer event occurs.
protocol PointerCaptureListenerHACK {
    OnPointerEvent(fuchsia.ui.input.PointerEvent event);
};

// |Presentation.RegisterMediaButtonsListener| will consume this listener interface
// and call |OnMediaButtonsEvent| when the registered media buttons event occurs.
protocol MediaButtonsListener {
    OnMediaButtonsEvent(fuchsia.ui.input.MediaButtonsEvent event);
};

// Allows clients of Presenter.Present() to control a presentation.
// Experimental.
[Discoverable]
protocol Presentation {
    // Enable or disable clipping for the Scenic renderer associated with the
    // presentation.
    EnableClipping(bool enabled);

    UseOrthographicView();
    UsePerspectiveView();

    // Set parameters such as the shadow algorithm used to render the scene.
    // NOTE: a single param would be better than an array; see TO-529.
    SetRendererParams(vector<fuchsia.ui.gfx.RendererParam> params);

    // Override the intended usage of the display.
    SetDisplayUsage(DisplayUsage usage);

    // Rotates the display.
    SetDisplayRotation(float32 display_rotation_degrees, bool animate);

    // Override the dimensions of the display. Values must be less than the actual
    // size of the display. If either of the values are 0, then they are ignored
    // and the actual size of the display is used.
    SetDisplaySizeInMm(float32 width_in_mm, float32 height_in_mm);

    // This call exists so that base shell can capture hotkeys and do special
    // things with it (e.g., switch a session shell). Phase and modifiers are always
    // matched, and valid (non-zero) code points are matched. If there is no
    // valid code point, the filter will match against the hid usage value.
    // The full KeyboardEvent is supplied to |listener|'s OnEvent.
    // TODO: Figure out the feasibility of this feature and the best place to put
    // it.
    CaptureKeyboardEventHACK(fuchsia.ui.input.KeyboardEvent event_to_capture,
                             KeyboardCaptureListenerHACK listener);

    // This call exists so that base shell can capture pointer events.
    // TODO: Figure out the feasibility of this feature and the best place to put
    // it. This call will be replaced by gesture disambiguation system in future.
    CapturePointerEventsHACK(PointerCaptureListenerHACK listener);

    // TODO(SCN-650): Determine better place for PresentationMode API.
    GetPresentationMode() -> (PresentationMode mode);
    SetPresentationModeListener(PresentationModeListener listener);

    // Registers a listener for media buttons events.
    RegisterMediaButtonsListener(MediaButtonsListener listener);

    // EXPERIMENTAL. Inject pointer events into input stream. This WILL go
    // away. Used exclusively by Session Shells to test focus navigation.
    // TODO(SCN-1186): Delete when RequestFocus is available.
    [Transitional]
    InjectPointerEventHACK(fuchsia.ui.input.PointerEvent event);
};

// Screen modes that can be detected via sensor data.
// N.B. We use accelerometers to measure gravity when at rest, so detection is
// limited to earth-relative orientations.
enum PresentationMode {
    CLOSED = 0;
    LAPTOP = 1;
    TABLET = 2;
    TENT = 3;
};

// Tell client that the screen mode has changed, according to sensors.
// N.B. There can be a race where the actual mode continues to change, after
// the listener has been notified. The client must call GetPresentationMode(),
// which will return the latest detected mode.
protocol PresentationModeListener {
    OnModeChanged();
};