| /* |
| * Copyright 2019 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 androidx.camera.core; |
| |
| import androidx.annotation.FloatRange; |
| import androidx.annotation.NonNull; |
| import androidx.annotation.RestrictTo; |
| |
| import com.google.common.util.concurrent.ListenableFuture; |
| |
| import java.util.concurrent.CancellationException; |
| import java.util.concurrent.Future; |
| |
| /** |
| * The {@link CameraControl} provides various asynchronous operations like zoom, focus and |
| * metering which affects output of all {@link UseCase}s currently bound to that camera. |
| * |
| * <p>The application can retrieve the {@link CameraControl} instance via |
| * {@link Camera#getCameraControl()}. {@link CameraControl} is ready to start operations |
| * immediately after {@link Camera} is retrieved and {@link UseCase}s are bound to that camera. |
| * When all {@link UseCase}s are unbound, or when camera is closing or closed because |
| * lifecycle onStop happens, the {@link CameraControl} will reject all operations. |
| * |
| * <p>Each method Of {@link CameraControl} returns a {@link ListenableFuture} which apps can use to |
| * check the asynchronous result. If the operation is not allowed in current state, the returned |
| * {@link ListenableFuture} will fail immediately with |
| * {@link CameraControl.OperationCanceledException}. |
| */ |
| public interface CameraControl { |
| /** |
| * Enable the torch or disable the torch. |
| * |
| * <p>{@link CameraInfo#getTorchState()} can be used to query the torch state. |
| * If the camera doesn't have a flash unit (see {@link CameraInfo#hasFlashUnit()}), then the |
| * call will do nothing, the returned {@link ListenableFuture} will complete immediately with |
| * a failed result and the torch state will be {@link TorchState#OFF}. |
| * |
| * <p>When the torch is enabled, the torch will remain enabled during photo capture regardless |
| * of the flashMode setting. When the torch is disabled, flash will function as the flash mode |
| * set by either {@link ImageCapture#setFlashMode(int)} or |
| * {@link ImageCapture.Builder#setFlashMode(int)}. |
| * |
| * @param torch true to turn on the torch, false to turn it off. |
| * @return A {@link ListenableFuture} which is successful when the torch was changed to the |
| * value specified. It fails when it is unable to change the torch state. |
| */ |
| @NonNull |
| ListenableFuture<Void> enableTorch(boolean torch); |
| |
| /** |
| * Starts a focus and metering action configured by the {@link FocusMeteringAction}. |
| * |
| * <p>It will trigger an auto focus action and enable AF/AE/AWB metering regions. The action |
| * is configured by a {@link FocusMeteringAction} which contains the configuration of |
| * multiple AF/AE/AWB {@link MeteringPoint}s and an auto-cancel duration. See |
| * {@link FocusMeteringAction} for more details. |
| * |
| * <p>Only one {@link FocusMeteringAction} is allowed to run at a time. If multiple |
| * {@link FocusMeteringAction} are executed in a row, only the latest one will work and |
| * other actions will be cancelled. |
| * |
| * <p>If the {@link FocusMeteringAction} specifies more AF/AE/AWB points than what is |
| * supported on the current device, only the first point and then in order up to the number of |
| * points supported by the device will be enabled. |
| * |
| * <p>If none of the points with either AF/AE/AWB can be supported on the device or none of |
| * the points generates valid metering rectangles, the returned {@link ListenableFuture} in |
| * {@link CameraControl#startFocusAndMetering(FocusMeteringAction)} will fail immediately. |
| * |
| * @see FocusMeteringAction |
| * |
| * @param action the {@link FocusMeteringAction} to be executed. |
| * @return A {@link ListenableFuture} which completes with {@link FocusMeteringAction} when |
| * auto focus is done and AF/AE/AWB regions are updated. In case AF points are not added, |
| * auto focus will not be triggered and this {@link ListenableFuture} completes when |
| * AE/AWB regions are updated. |
| * |
| */ |
| @NonNull |
| ListenableFuture<FocusMeteringResult> startFocusAndMetering( |
| @NonNull FocusMeteringAction action); |
| |
| /** |
| * Cancels current {@link FocusMeteringAction} and clears AF/AE/AWB regions. |
| * |
| * <p>Clear the AF/AE/AWB regions and update current AF mode to continuous AF (if |
| * supported). If current {@link FocusMeteringAction} has not completed, the returned |
| * {@link ListenableFuture} in {@link #startFocusAndMetering} will fail with |
| * {@link OperationCanceledException}. |
| * |
| * @return A {@link ListenableFuture} which completes when the AF/AE/AWB regions is clear and AF |
| * mode is set to continuous focus (if supported). |
| */ |
| @NonNull |
| ListenableFuture<Void> cancelFocusAndMetering(); |
| |
| /** |
| * Sets current zoom by ratio. |
| * |
| * <p>It modifies both current zoomRatio and linearZoom so if apps are observing |
| * zoomRatio or linearZoom, they will get the update as well. If the ratio is |
| * smaller than {@link ZoomState#getMinZoomRatio()} or larger than |
| * {@link ZoomState#getMaxZoomRatio()}, the returned {@link ListenableFuture} will fail with |
| * {@link IllegalArgumentException} and it won't modify current zoom ratio. It is the |
| * applications' duty to clamp the ratio. |
| * |
| * @return a {@link ListenableFuture} which is finished when current repeating request |
| * result contains the requested zoom ratio. It fails with |
| * {@link OperationCanceledException} if there is newer value being set or camera is closed. If |
| * the ratio is out of range, it fails with {@link IllegalArgumentException}. |
| */ |
| @NonNull |
| ListenableFuture<Void> setZoomRatio(float ratio); |
| |
| /** |
| * Sets current zoom by a linear zoom value ranging from 0f to 1.0f. LinearZoom 0f represents |
| * the minimum zoom while linearZoom 1.0f represents the maximum zoom. The advantage of |
| * linearZoom is that it ensures the field of view (FOV) varies linearly with the linearZoom |
| * value, for use with slider UI elements (while {@link #setZoomRatio(float)} works well |
| * for pinch-zoom gestures). |
| * |
| * <p>It modifies both current zoomRatio and linearZoom so if apps are observing |
| * zoomRatio or linearZoom, they will get the update as well. If the linearZoom is not in |
| * the range [0..1], the returned {@link ListenableFuture} will fail with |
| * {@link IllegalArgumentException} and it won't modify current linearZoom and zoomRatio. It is |
| * application's duty to clamp the linearZoom within [0..1]. |
| * |
| * @return a {@link ListenableFuture} which is finished when current repeating request |
| * result contains the requested linearZoom. It fails with |
| * {@link OperationCanceledException} if there is newer value being set or camera is closed. |
| * If linearZoom is not in range [0..1], it fails with {@link IllegalArgumentException}. |
| * |
| */ |
| @NonNull |
| ListenableFuture<Void> setLinearZoom(@FloatRange(from = 0f, to = 1f) float linearZoom); |
| |
| /** |
| * An exception representing a failure that the operation is canceled which might be caused by |
| * a new value is set or camera is closed. |
| * |
| * <p>This is different from {@link CancellationException}. While |
| * {@link CancellationException} means the {@link ListenableFuture} was cancelled by |
| * {@link Future#cancel(boolean)}, {@link OperationCanceledException} occurs when there is |
| * something wrong inside CameraControl and it has to cancel the operation. |
| */ |
| final class OperationCanceledException extends Exception { |
| /** @hide */ |
| @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) |
| public OperationCanceledException(@NonNull String message) { |
| super(message); |
| } |
| |
| /** @hide */ |
| @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) |
| public OperationCanceledException(@NonNull String message, @NonNull Throwable cause) { |
| super(message, cause); |
| } |
| } |
| } |