Added setter for OverlayView's cropViewRect in order to make possible to show custom cropping rect when uCrop starts

sample/src/main/java/com/yalantis/ucrop/sample/SampleActivity.java

@@ -366,6 +366,7 @@ Tune everything (ﾉ◕ヮ◕)ﾉ*:･ﾟ✧
         options.setCropGridColor(Color.GREEN);
         options.setCropGridColumnCount(2);
         options.setCropGridRowCount(1);
+        options.setCropViewRectInImageSpace(new RectF(100, 100, 500, 500));
         options.setToolbarCropDrawable(R.drawable.your_crop_icon);
         options.setToolbarCancelDrawable(R.drawable.your_cancel_icon);
 

ucrop/src/main/java/com/yalantis/ucrop/UCrop.java

@@ -6,6 +6,7 @@
 import android.content.Context;
 import android.content.Intent;
 import android.graphics.Bitmap;
+import android.graphics.RectF;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
@@ -280,6 +281,7 @@ public static class Options {
         public static final String EXTRA_CROP_GRID_COLUMN_COUNT = EXTRA_PREFIX + ".CropGridColumnCount";
         public static final String EXTRA_CROP_GRID_COLOR = EXTRA_PREFIX + ".CropGridColor";
         public static final String EXTRA_CROP_GRID_STROKE_WIDTH = EXTRA_PREFIX + ".CropGridStrokeWidth";
+        public static final String EXTRA_CROP_VIEW_RECT_IN_IMAGE_SPACE = EXTRA_PREFIX + ".CropViewRectInImageSpace";
 
         public static final String EXTRA_TOOL_BAR_COLOR = EXTRA_PREFIX + ".ToolbarColor";
         public static final String EXTRA_STATUS_BAR_COLOR = EXTRA_PREFIX + ".StatusBarColor";
@@ -433,6 +435,29 @@ public void setCropGridStrokeWidth(@IntRange(from = 0) int width) {
             mOptionBundle.putInt(EXTRA_CROP_GRID_STROKE_WIDTH, width);
         }
 
+        /**
+         *  <p>This method will accept a RectF with coordinates from the image space.</p><br>
+         *
+         *  <p>Example: Useful if you want want to process the image and detect objects within before
+         *  opening uCrop in order to highlight desired cropping area, like for example document
+         *  detection and you want to display the cropping Rect over the detected document when
+         *  uCrop starts.</p><br>
+         *
+         *  <p>Passing your desired RectF will result in the
+         *  {@link com.yalantis.ucrop.view.OverlayView}'s highlighting the desired area.
+         *  This rect will be automatically converted to a RectF that corresponds with the image's
+         *  coordinates inside the view.</p><br>
+         *
+         *  <p>This must be used in combination with {@link #setMaxBitmapSize} to set a greater bitmap
+         *  size, otherwise bigger images will be downscaled and coordinates of objects detected
+         *  in input image space won't match with the new downscaled image ones.</p><br>
+         *
+         * @param rect - desired crop view rect in image space.
+         */
+        public void setCropViewRectInImageSpace(@NonNull RectF rect) {
+            mOptionBundle.putParcelable(EXTRA_CROP_VIEW_RECT_IN_IMAGE_SPACE, rect);
+        }
+
         /**
          * @param color - desired resolved color of the toolbar
          */

ucrop/src/main/java/com/yalantis/ucrop/UCropActivity.java

@@ -4,6 +4,7 @@
 import android.content.Intent;
 import android.graphics.Bitmap;
 import android.graphics.PorterDuff;
+import android.graphics.RectF;
 import android.graphics.drawable.Animatable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
@@ -27,6 +28,7 @@
 
 import com.yalantis.ucrop.callback.BitmapCropCallback;
 import com.yalantis.ucrop.model.AspectRatio;
+import com.yalantis.ucrop.util.RectUtils;
 import com.yalantis.ucrop.util.SelectedStateListDrawable;
 import com.yalantis.ucrop.view.CropImageView;
 import com.yalantis.ucrop.view.GestureCropImageView;
@@ -380,6 +382,17 @@ public void onScale(float currentScale) {
         @Override
         public void onLoadComplete() {
             mUCropView.animate().alpha(1).setDuration(300).setInterpolator(new AccelerateInterpolator());
+            if (getIntent().hasExtra(UCrop.Options.EXTRA_CROP_VIEW_RECT_IN_IMAGE_SPACE)) {
+                RectF rectInImageSpace = getIntent().getParcelableExtra(UCrop.Options.EXTRA_CROP_VIEW_RECT_IN_IMAGE_SPACE);
+
+                int viewWidth = mGestureCropImageView.getWidth();
+                int viewHeight = mGestureCropImageView.getHeight();
+
+                Drawable drawable = mGestureCropImageView.getDrawable();
+
+                RectF cropViewRect = RectUtils.convertImageSpaceRectToCropViewRect(rectInImageSpace, viewWidth, viewHeight, drawable);
+                mOverlayView.setCropViewRect(cropViewRect);
+            }
             mBlockingView.setClickable(false);
             mShowLoader = false;
             supportInvalidateOptionsMenu();

ucrop/src/main/java/com/yalantis/ucrop/UCropFragment.java

@@ -4,6 +4,8 @@
 import android.content.Intent;
 import android.graphics.Bitmap;
 import android.graphics.PorterDuff;
+import android.graphics.RectF;
+import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.text.TextUtils;
@@ -19,6 +21,7 @@
 
 import com.yalantis.ucrop.callback.BitmapCropCallback;
 import com.yalantis.ucrop.model.AspectRatio;
+import com.yalantis.ucrop.util.RectUtils;
 import com.yalantis.ucrop.util.SelectedStateListDrawable;
 import com.yalantis.ucrop.view.CropImageView;
 import com.yalantis.ucrop.view.GestureCropImageView;
@@ -284,6 +287,17 @@ public void onScale(float currentScale) {
         @Override
         public void onLoadComplete() {
             mUCropView.animate().alpha(1).setDuration(300).setInterpolator(new AccelerateInterpolator());
+            if (getArguments().containsKey(UCrop.Options.EXTRA_CROP_VIEW_RECT_IN_IMAGE_SPACE)) {
+                RectF rectInImageSpace = getArguments().getParcelable(UCrop.Options.EXTRA_CROP_VIEW_RECT_IN_IMAGE_SPACE);
+
+                int viewWidth = mGestureCropImageView.getWidth();
+                int viewHeight = mGestureCropImageView.getHeight();
+
+                Drawable drawable = mGestureCropImageView.getDrawable();
+
+                RectF cropViewRect = RectUtils.convertImageSpaceRectToCropViewRect(rectInImageSpace, viewWidth, viewHeight, drawable);
+                mOverlayView.setCropViewRect(cropViewRect);
+            }
             mBlockingView.setClickable(false);
             callback.loadingProgress(false);
         }

ucrop/src/main/java/com/yalantis/ucrop/util/RectUtils.java

@@ -1,6 +1,7 @@
 package com.yalantis.ucrop.util;
 
 import android.graphics.RectF;
+import android.graphics.drawable.Drawable;
 
 public class RectUtils {
 
@@ -69,4 +70,32 @@ public static RectF trapToRect(float[] array) {
         return r;
     }
 
+    /**
+     * Takes an rect in image space (received rect can only be in image space, since you can't
+     * know the view's width and height from the outside). So in case you want to process the image
+     * outside uCrop, you will only have coordinates in image space and not in uCrop's view space.
+     * Those need to be converted.
+     *
+     * @param rectInImageSpace RectF in image space
+     * @param viewWidth The view's width
+     * @param viewHeight The view's height
+     * @param drawable The drawable object to retrieve drawable width and height
+     *
+     * @return A new RectF object representing how the RectF should be drawn on screen.
+     */
+    public static RectF convertImageSpaceRectToCropViewRect(RectF rectInImageSpace, int viewWidth, int viewHeight, Drawable drawable) {
+        int drawableWidth = drawable.getIntrinsicWidth();
+        int drawableHeight = drawable.getIntrinsicHeight();
+
+        double widthAspectRatio = (double) viewWidth / drawableWidth;
+        double heightAspectRatio = (double) viewHeight / drawableHeight;
+
+        return new RectF(
+                (float) (rectInImageSpace.left * widthAspectRatio),
+                (float) (rectInImageSpace.top * heightAspectRatio),
+                (float) (rectInImageSpace.right * widthAspectRatio),
+                (float) (rectInImageSpace.bottom * heightAspectRatio)
+        );
+    }
+
 }

ucrop/src/main/java/com/yalantis/ucrop/view/OverlayView.java

@@ -105,6 +105,13 @@ public RectF getCropViewRect() {
         return mCropViewRect;
     }
 
+    /**
+     * Setter for mCropViewRect. Can be used to set an initial value for the mCropViewRect.
+     */
+    public void setCropViewRect(RectF rect) {
+        mCropViewRect.set(rect);
+    }
+
     @Deprecated
     /***
      * Please use the new method {@link #getFreestyleCropMode() getFreestyleCropMode} method as we have more than 1 freestyle crop mode.
@@ -233,16 +240,18 @@ public void setTargetAspectRatio(final float targetAspectRatio) {
      * {@link #mCropViewRect} is used to draw crop bounds - uses padding.
      */
     public void setupCropBounds() {
-        int height = (int) (mThisWidth / mTargetAspectRatio);
-        if (height > mThisHeight) {
-            int width = (int) (mThisHeight * mTargetAspectRatio);
-            int halfDiff = (mThisWidth - width) / 2;
-            mCropViewRect.set(getPaddingLeft() + halfDiff, getPaddingTop(),
-                    getPaddingLeft() + width + halfDiff, getPaddingTop() + mThisHeight);
-        } else {
-            int halfDiff = (mThisHeight - height) / 2;
-            mCropViewRect.set(getPaddingLeft(), getPaddingTop() + halfDiff,
-                    getPaddingLeft() + mThisWidth, getPaddingTop() + height + halfDiff);
+        if (mCropViewRect.isEmpty()) {
+            int height = (int) (mThisWidth / mTargetAspectRatio);
+            if (height > mThisHeight) {
+                int width = (int) (mThisHeight * mTargetAspectRatio);
+                int halfDiff = (mThisWidth - width) / 2;
+                mCropViewRect.set(getPaddingLeft() + halfDiff, getPaddingTop(),
+                        getPaddingLeft() + width + halfDiff, getPaddingTop() + mThisHeight);
+            } else {
+                int halfDiff = (mThisHeight - height) / 2;
+                mCropViewRect.set(getPaddingLeft(), getPaddingTop() + halfDiff,
+                        getPaddingLeft() + mThisWidth, getPaddingTop() + height + halfDiff);
+            }
         }
 
         if (mCallback != null) {