[Android] Add setPreferredFramesPerSecond for MapView

5 files changed, 79 insertions, 4 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java
index fc9418c2d9..cef7242ff3 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java
@@ -426,6 +426,18 @@ public class MapView extends FrameLayout implements NativeMapView.ViewCallback {
   }
 
   /**
+   *  The preferred frame rate at which the map view is rendered,
+   *  but it can't excess the ability of device hardware.
+   *
+   * @param preferredFramesPerSecond  Can be set to arbitrary integer values.
+   */
+  public void setPreferredFramesPerSecond(int preferredFramesPerSecond) {
+    if (mapRenderer != null) {
+      mapRenderer.setPreferredFramesPerSecond(preferredFramesPerSecond);
+    }
+  }
+
+  /**
    * Returns if the map has been destroyed.
    * <p>
    * This method can be used to determine if the result of an asynchronous operation should be set.
diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/renderer/MapRenderer.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/renderer/MapRenderer.java
index 9617f94fce..9947fd3bc5 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/renderer/MapRenderer.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/renderer/MapRenderer.java
@@ -5,6 +5,7 @@ import android.support.annotation.CallSuper;
 import android.support.annotation.Keep;
 
 import android.support.annotation.NonNull;
+
 import com.mapbox.mapboxsdk.log.Logger;
 import com.mapbox.mapboxsdk.maps.MapboxMap;
 import com.mapbox.mapboxsdk.storage.FileSource;
@@ -26,7 +27,7 @@ public abstract class MapRenderer implements MapRendererScheduler {
 
   // Holds the pointer to the native peer after initialisation
   private long nativePtr = 0;
-
+  private int preferredFramesPerSecond = Integer.MAX_VALUE;
   private MapboxMap.OnFpsChangedListener onFpsChangedListener;
 
   public MapRenderer(@NonNull Context context, String localIdeographFontFamily) {
@@ -121,12 +122,38 @@ public abstract class MapRenderer implements MapRendererScheduler {
   private void updateFps() {
     frames++;
     long currentTime = System.nanoTime();
-    double fps = 0;
-    if (currentTime - timeElapsed >= 1) {
-      fps = frames / ((currentTime - timeElapsed) / 1E9);
+    long timeCost = currentTime - timeElapsed;
+
+    if (timeCost >= 1) {
+      double fps = frames / ((timeCost) / 1E9);
+      if (fps > preferredFramesPerSecond) {
+        try {
+          long millis = (long) (timeCost / 1E6 * (fps - preferredFramesPerSecond) / fps);
+          Thread.sleep(millis);
+        } catch (InterruptedException ex) {
+          ex.printStackTrace();
+        }
+        long newCurrentTime = System.nanoTime();
+        timeCost = newCurrentTime - timeElapsed;
+        fps = frames / ((timeCost) / 1E9);
+      }
       onFpsChangedListener.onFpsChanged(fps);
       timeElapsed = currentTime;
       frames = 0;
     }
   }
+
+  /**
+   * The preferred frame rate at which this render is rendered,
+   * but it can't excess the ability of device hardware.
+   *
+   * @param preferredFramesPerSecond Can be set to arbitrary integer values.
+   */
+  public void setPreferredFramesPerSecond(int preferredFramesPerSecond) {
+    if (preferredFramesPerSecond <= 0) {
+      // Not valid, just return
+      return;
+    }
+    this.preferredFramesPerSecond = preferredFramesPerSecond;
+  }
 }
diff --git a/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/maplayout/DebugModeActivity.java b/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/maplayout/DebugModeActivity.java
index f3ffedcd23..310b0a88a0 100644
--- a/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/maplayout/DebugModeActivity.java
+++ b/platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/maplayout/DebugModeActivity.java
@@ -28,6 +28,7 @@ import java.util.List;
 import java.util.Locale;
 
 import com.mapbox.mapboxsdk.testapp.utils.IdleZoomListener;
+
 import timber.log.Timber;
 
 import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.visibility;
@@ -62,6 +63,7 @@ public class DebugModeActivity extends AppCompatActivity implements OnMapReadyCa
     setupMapView(savedInstanceState);
     setupDebugChangeView();
     setupStyleChangeView();
+    setupFpsChangeView();
   }
 
   private void setupToolbar() {
@@ -167,6 +169,15 @@ public class DebugModeActivity extends AppCompatActivity implements OnMapReadyCa
     });
   }
 
+  private void setupFpsChangeView() {
+    findViewById(R.id.fps_30).setOnClickListener(view -> {
+      mapView.setPreferredFramesPerSecond(30);
+    });
+    findViewById(R.id.fps_60).setOnClickListener(view -> {
+      mapView.setPreferredFramesPerSecond(60);
+    });
+  }
+
   @Override
   public boolean onOptionsItemSelected(MenuItem item) {
     return actionBarDrawerToggle.onOptionsItemSelected(item) || super.onOptionsItemSelected(item);
diff --git a/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/layout/activity_debug_mode.xml b/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/layout/activity_debug_mode.xml
index c6f3c0e3f2..e6fbceecc6 100644
--- a/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/layout/activity_debug_mode.xml
+++ b/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/layout/activity_debug_mode.xml
@@ -79,6 +79,29 @@
             app:layout_anchor="@id/bottom_sheet"
             app:layout_anchorGravity="bottom|end"/>
 
+        <Button
+            android:id="@+id/fps_60"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="end|start"
+            app:backgroundTint="@color/primary"
+            android:layout_margin="@dimen/fab_margin"
+            android:text="@string/fps60"
+            app:layout_anchor="@id/bottom_sheet"
+            app:layout_anchorGravity="top|end"/>
+
+        <Button
+            android:id="@+id/fps_30"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="top|end"
+            android:layout_marginBottom="82dp"
+            app:backgroundTint="@color/primary"
+            android:layout_marginEnd="@dimen/fab_margin"
+            android:layout_marginRight="@dimen/fab_margin"
+            android:text="@string/fps30"
+            app:layout_anchor="@id/fps_60"
+            app:layout_anchorGravity="top"/>
     </android.support.design.widget.CoordinatorLayout>
 
     <android.support.design.widget.NavigationView
diff --git a/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/strings.xml b/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/strings.xml
index 15a916fac9..45048f8b07 100644
--- a/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/strings.xml
+++ b/platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/strings.xml
@@ -1,4 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string name="app_name">Mapbox Android SDK TestApp</string>
+    <string name="fps30">fps30</string>
+    <string name="fps60">fps60</string>
 </resources>