[android] - add logo resize to MapSnapshotter

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/snapshotter/MapSnaphotUtil.java

@@ -0,0 +1,29 @@
+package com.mapbox.mapboxsdk.snapshotter;
+
+import android.graphics.BitmapFactory;
+
+class MapSnaphotUtil {
+
+  static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
+    // Raw height and width of image
+    final int height = options.outHeight;
+    final int width = options.outWidth;
+    int inSampleSize = 1;
+
+    if (height > reqHeight || width > reqWidth) {
+
+      final int halfHeight = height / 2;
+      final int halfWidth = width / 2;
+
+      // Calculate the largest inSampleSize value that is a power of 2 and keeps both
+      // height and width larger than the requested height and width.
+      while ((halfHeight / inSampleSize) >= reqHeight
+        && (halfWidth / inSampleSize) >= reqWidth) {
+        inSampleSize *= 2;
+      }
+    }
+    return inSampleSize;
+  }
+
+
+}

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/snapshotter/MapSnapshotter.java

@@ -7,6 +7,7 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
+import android.util.DisplayMetrics;
 
 import com.mapbox.mapboxsdk.R;
 import com.mapbox.mapboxsdk.camera.CameraPosition;
@@ -55,7 +56,7 @@ public interface ErrorHandler {
     void onError(String error);
   }
 
-  private static final int LOGO_MARGIN_PX = 4;
+  private static final int LOGO_MARGIN_DP = 4;
 
   // Holds the pointer to JNI NativeMapView
   private long nativePtr = 0;
@@ -262,10 +263,34 @@ public void cancel() {
   }
 
   protected void addOverlay(Bitmap original) {
-    float margin = context.getResources().getDisplayMetrics().density * LOGO_MARGIN_PX;
+    DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
+    float margin = displayMetrics.density * LOGO_MARGIN_DP;
     Canvas canvas = new Canvas(original);
-    Bitmap logo = BitmapFactory.decodeResource(context.getResources(), R.drawable.mapbox_logo_icon, null);
-    canvas.drawBitmap(logo, margin, original.getHeight() - (logo.getHeight() + margin), null);
+
+    // Decode just the boundaries
+    BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
+    bitmapOptions.inJustDecodeBounds = true;
+    BitmapFactory.decodeResource(context.getResources(), R.drawable.mapbox_logo_icon, bitmapOptions);
+    int srcWidth = bitmapOptions.outWidth;
+    int srcHeight = bitmapOptions.outHeight;
+
+    // Ratio, preferred dimensions and resulting sample size
+    float widthRatio = displayMetrics.widthPixels / original.getWidth();
+    float heightRatio = displayMetrics.heightPixels / original.getHeight();
+    float prefWidth = srcWidth / widthRatio;
+    float prefHeight = srcHeight / heightRatio;
+    int sampleSize = MapSnaphotUtil.calculateInSampleSize(bitmapOptions, (int) prefWidth, (int) prefHeight);
+
+    // Scale bitmap
+    bitmapOptions.inJustDecodeBounds = false;
+    bitmapOptions.inScaled = true;
+    bitmapOptions.inSampleSize = sampleSize;
+    bitmapOptions.inDensity = srcWidth;
+    bitmapOptions.inTargetDensity = (int) prefWidth * bitmapOptions.inSampleSize;
+    Bitmap logo = BitmapFactory.decodeResource(context.getResources(), R.drawable.mapbox_logo_icon, bitmapOptions);
+
+    float scaledHeight = bitmapOptions.outHeight * heightRatio / bitmapOptions.inSampleSize;
+    canvas.drawBitmap(logo, margin, original.getHeight() - scaledHeight - margin, null);
   }
 
   /**