Add Capture Latency Estiamte Indicator for Extension

[jsaund]

• camera extension can query for the realtime capture latency estimate
• display this as a hint to the user how long to hold still for

[madebymozart]

Looks Good

[yrezgui]

/gemini summarize

[gemini-code-assist]

Summary of Changes

This pull request introduces a capture latency estimate indicator for the camera extension in the CameraXExtensions app. The extension queries for the real-time capture latency estimate and displays it as a hint to the user, indicating how long they should hold still for optimal image capture. The changes involve modifying the MainActivity.kt, CameraUiState.kt, CameraExtensionsScreen.kt, CameraExtensionsViewModel.kt, CameraPreviewScreenViewState.kt, activity_main.xml, and strings.xml files.

Highlights

• Capture Latency Estimate: The pull request adds the ability for the camera extension to query for the real-time capture latency estimate.
• User Interface Hint: The capture latency estimate is displayed as a hint to the user, informing them how long to hold still.
• UI Integration: A new TextView (latencyEstimateIndicator) is added to the layout to display the latency estimate, with associated logic to show/hide it based on the estimated latency.
• Camera State Management: The CameraUiState is updated to include the realtimeCaptureLatencyEstimate, and the CameraState enum is extended with PREVIEW_ACTIVE.
• Realtime Latency Observation: A coroutine job is started when the preview is active to observe and update the realtime latency estimate.

Changelog

Click here to see the changelog

• CameraXExtensions/app/src/main/java/com/example/android/cameraxextensions/MainActivity.kt
  • Imported ImageCaptureLatencyEstimate from androidx.camera.core.
  • Added CAPTURE_LATENCY_INDICATOR_THRESHOLD_MS constant.
  • Added logging for camera state changes.
  • Implemented logic to show/hide the latency estimate indicator based on the realtimeCaptureLatencyEstimate.
  • Updated the UI state when the camera preview is active to show or hide the latency indicator based on the latency estimate.
• CameraXExtensions/app/src/main/java/com/example/android/cameraxextensions/model/CameraUiState.kt
  • Imported ImageCaptureLatencyEstimate from androidx.camera.core.
  • Added realtimeCaptureLatencyEstimate property to CameraUiState.
  • Added PREVIEW_ACTIVE state to the CameraState enum.
• CameraXExtensions/app/src/main/java/com/example/android/cameraxextensions/ui/CameraExtensionsScreen.kt
  • Imported TimeUnit and roundToInt.
  • Added latencyEstimateIndicator TextView.
  • Implemented showLatencyEstimate and hideLatencyEstimate functions to control the visibility and text of the latency indicator.
  • Updated the bindState function to show/hide the latency indicator based on the latencyEstimateIndicatorViewState.
• CameraXExtensions/app/src/main/java/com/example/android/cameraxextensions/viewmodel/CameraExtensionsViewModel.kt
  • Imported Job, delay, isActive, asFlow, and CoroutineScope.
  • Added REALTIME_LATENCY_UPDATE_INTERVAL_MILLIS constant.
  • Added realtimeLatencyEstimateJob to manage the latency observation coroutine.
  • Implemented observeRealtimeLatencyEstimate to periodically update the latency estimate.
  • Updated startPreview to start the latency observation job when the preview is active.
  • Updated stopPreview and switchCamera to cancel the latency observation job.
  • Updated capturePhoto to cancel the latency observation job.
  • Implemented updateRealtimeCaptureLatencyEstimate to fetch and update the latency estimate in the UI state.
• CameraXExtensions/app/src/main/java/com/example/android/cameraxextensions/viewstate/CameraPreviewScreenViewState.kt
  • Added LatencyEstimateIndicatorViewState data class.
  • Added latencyEstimateIndicatorViewState property to CameraPreviewScreenViewState.
  • Added showLatencyEstimateIndicator and hideLatencyEstimateIndicator functions to update the latencyEstimateIndicatorViewState.
• CameraXExtensions/app/src/main/res/layout/activity_main.xml
  • Added latencyEstimateIndicator TextView to the layout.
• CameraXExtensions/app/src/main/res/values/strings.xml
  • Added latency_estimate string resource.
• build.gradle
  • Updated gradle version from 8.1.1 to 8.7.3

Activity

• madebymozart left a review with 'Looks Good'
• yrezgui requested a summary from gemini-code-assist