Implement the new Photo picker, part two.

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/PickerBitmapView.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.photo_picker;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
+import android.support.annotation.Nullable;
+import android.support.v4.content.ContextCompat;
+import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.animation.Animation;
+import android.view.animation.Transformation;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.widget.selection.SelectableItemView;
+import org.chromium.chrome.browser.widget.selection.SelectionDelegate;
+
+import java.util.List;
+
+/**
+ * A container class for a view showing a photo in the photo picker.
+ */
+public class PickerBitmapView extends SelectableItemView<PickerBitmap> {
+    // Our context.
+    private Context mContext;
+
+    // Our parent category.
+    private PickerCategoryView mCategoryView;
+
+    // Our selection delegate.
+    private SelectionDelegate<PickerBitmap> mSelectionDelegate;
+
+    // The request details (meta-data) for the bitmap shown.
+    private PickerBitmap mRequest;
+
+    // The image view containing the bitmap.
+    private ImageView mIconView;
+
+    // The little shader in the top left corner (provides backdrop for selection ring for
+    // unfavorable image backgrounds).
+    private View mScrim;
+
+    // The view behind the image, representing the selection border.
+    private View mBorderView;
+
+    // The control that signifies the image has been selected.
+    private ImageView mSelectedView;
+
+    // The control that signifies the image has not been selected.
+    private ImageView mUnselectedView;
+
+    // The camera/gallery special tile (with icon as drawable).
+    private TextView mSpecialTile;
+
+    // Whether the image has been loaded already.
+    private boolean mImageLoaded;
+
+    // The amount to use for the border.
+    private int mBorder;
+
+    /**
+     * A resize animation class for the images (shrinks the image on selection).
+     */
+    private static class ResizeWidthAnimation extends Animation {
+        // The view to animate size changes for.
+        private View mView;
+
+        // The starting size of the view.
+        private int mStartingSize;
+
+        // The target size we want to achieve.
+        private int mTargetSize;
+
+        /**
+         * The ResizeWidthAnimation constructor.
+         * @param view The view to animate size changes for.
+         * @param size The target size we want to achieve.
+         */
+        public ResizeWidthAnimation(View view, int size) {
+            mView = view;
+            mStartingSize = view.getWidth();
+            mTargetSize = size;
+        }
+
+        @Override
+        protected void applyTransformation(float interpolatedTime, Transformation transformation) {
+            int newSize = mStartingSize + (int) ((mTargetSize - mStartingSize) * interpolatedTime);
+            int padding = (Math.max(mStartingSize, mTargetSize) - newSize) / 2;
+
+            mView.getLayoutParams().height = newSize;
+            mView.getLayoutParams().width = newSize;
+            // Create a border around the image.
+            if (mView instanceof ImageView) {
+                addPaddingToParent(mView, padding);
+            }
+        }
+
+        @Override
+        public boolean willChangeBounds() {
+            return true;
+        }
+    }
+
+    /**
+     * Constructor for inflating from XML.
+     */
+    public PickerBitmapView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mContext = context;
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+
+        if (mCategoryView == null) return; // Android Studio calls onMeasure to draw the widget.

[Theresa, 2017/03/28 20:40:28]

Why does it matter if Android Studio calls onMeasure? This comment should be
more applicable to Chromium. I think it's probably not necessary -- the early
return makes sense (to me) without it.

[Finnur, 2017/03/31 14:26:50]

Excellent. I worried it would not make sense without it. :)

+        int width = mCategoryView.getImageSize();
+        int height = mCategoryView.getImageSize();
+        setMeasuredDimension(width, height);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        mIconView = (ImageView) findViewById(R.id.bitmap_view);
+        mScrim = findViewById(R.id.scrim);
+        mBorderView = findViewById(R.id.border);
+        mSelectedView = (ImageView) findViewById(R.id.selected);
+        mUnselectedView = (ImageView) findViewById(R.id.unselected);
+        mSpecialTile = (TextView) findViewById(R.id.special_tile);
+    }
+
+    @Override
+    public void onClick() {

[Theresa, 2017/03/28 20:40:28]

We had to introduce some special handling for bookmark items that weren't
selectable (it's since been mostly removed), but maybe this indicates that
having some items that are not selectable in the list is an acceptable patter
than needs to be backed into the selection widget classes.

[Finnur, 2017/03/31 14:26:50]

Acknowledged.

[Theresa, 2017/03/31 18:05:55]

I was thinking about this incorrectly -- this actually looks correct to me. The
other selectable lists of things take some action other than selection on click.

[Finnur, 2017/04/03 17:30:29]

Acknowledged.

+        if (mRequest.type() == PickerBitmap.TileTypes.GALLERY) {
+            mCategoryView.showGallery();
+            return;
+        } else if (mRequest.type() == PickerBitmap.TileTypes.CAMERA) {
+            mCategoryView.showCamera();
+            return;
+        }
+
+        mSelectionDelegate.toggleSelectionForItem(mRequest);
+        setChecked(!super.isChecked());
+    }
+
+    @Override
+    public void setChecked(boolean checked) {
+        if (mRequest.type() != PickerBitmap.TileTypes.PICTURE) {
+            return;
+        }
+
+        super.setChecked(checked);
+        updateSelectionState();
+    }
+
+    @Override
+    public void onSelectionStateChange(List<PickerBitmap> selectedItems) {
+        boolean selected = selectedItems.contains(mRequest);
+
+        if (mRequest.type() != PickerBitmap.TileTypes.PICTURE) {
+            if (selected) mSelectionDelegate.toggleSelectionForItem(mRequest);
+            updateSelectionState();
+            return;
+        }
+
+        boolean checked = super.isChecked();
+
+        if (!mCategoryView.isMultiSelect() && !selected && checked) {
+            super.toggle();
+        }
+
+        updateSelectionState();
+
+        if (!mImageLoaded || selected == checked) {
+            return;
+        }
+
+        int size = selected && !checked ? mCategoryView.getImageSize() - 2 * mBorder
+                                        : mCategoryView.getImageSize();
+        if (size != mIconView.getWidth()) {
+            ResizeWidthAnimation animation = new ResizeWidthAnimation(mIconView, size);
+            animation.setDuration(100);

[Theresa, 2017/03/28 20:40:28]

nit: define this as a constant somewhere


In the future, a good way to break up a really large CL like this is to focus on
base implementation first and add things like animation in a follow-on.

[Finnur, 2017/03/31 14:26:50]

Done.

+            // TODO: Add MD interpolator
+            // animation.setInterpolator((mContext, R.interpolator.fast_out_linear_in);
+            mIconView.startAnimation(animation);
+        }
+    }
+
+    /**
+     * Pre-initializes the PickerBitmapView.
+     * @param categoryView The category view showing the images.
+     */
+    public void preInitialize(PickerCategoryView categoryView) {
+        mCategoryView = categoryView;
+        mSelectionDelegate = mCategoryView.getSelectionDelegate();
+        super.setSelectionDelegate(mSelectionDelegate);
+
+        mSelectedView.setImageBitmap(mCategoryView.getSelectionBitmap(true));
+        mUnselectedView.setImageBitmap(mCategoryView.getSelectionBitmap(false));
+
+        mBorder = (int) getResources().getDimension(R.dimen.file_picker_selected_padding);
+    }
+
+    /**
+     * Completes the initialization of the PickerBitmapView. Must be called before the image can
+     * respond to click events.
+     * @param request The request represented by this PickerBitmapView.
+     * @param thumbnail The Bitmap to use for the thumbnail (or null).
+     * @param placeholder Whether the image given is a placeholder or the actual image.
+     */
+    public void initialize(PickerBitmap request, @Nullable Bitmap thumbnail, boolean placeholder) {
+        resetTile();
+
+        mRequest = request;
+        setItem(request);
+        setThumbnailBitmap(thumbnail);
+        mImageLoaded = !placeholder;
+
+        updateSelectionState();
+
+        setOnClickListener(this);
+    }
+
+    /**
+     * Initialization for the special tiles (camera/gallery icon).
+     */
+    public void initializeSpecialTile() {
+        int size = mCategoryView.getImageSize();
+        Bitmap tile = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
+        tile.eraseColor(Color.argb(0, 0, 0, 0));
+
+        int iconBitmapId, labelStringId;
+        if (mRequest.type() == PickerBitmap.TileTypes.CAMERA) {
+            iconBitmapId = R.drawable.ic_photo_camera;
+            labelStringId = R.string.file_picker_camera;
+        } else {
+            iconBitmapId = R.drawable.ic_collections_black_24dp;
+            labelStringId = R.string.file_picker_browse;
+        }
+
+        Resources resources = mContext.getResources();
+        mSpecialTile.setText(labelStringId);
+        Bitmap icon = BitmapFactory.decodeResource(resources, iconBitmapId);
+        DisplayMetrics metrics = resources.getDisplayMetrics();
+        float pixels = 48 * ((float) metrics.densityDpi / DisplayMetrics.DENSITY_DEFAULT);

[Theresa, 2017/03/28 20:40:28]

Define a dimension in dimens.xml rather than programatically calculating the
pixels.

Is this scaling the 24dp assets to 48dp?

[Finnur, 2017/03/31 14:26:50]

Done.

+        BitmapDrawable drawable = new BitmapDrawable(
+                resources, Bitmap.createScaledBitmap(icon, (int) pixels, (int) pixels, true));

[Theresa, 2017/03/28 20:40:28]

Android will automatically scale for you if the ImageView's scale type is set
correctly.

[Finnur, 2017/03/31 14:26:50]

It is not obvious to me how to interpret this comment...

+        ApiCompatibilityUtils.setCompoundDrawablesRelativeWithIntrinsicBounds(
+                mSpecialTile, null, drawable, null, null);
+
+        initialize(mRequest, tile, false);
+
+        mSpecialTile.setVisibility(View.VISIBLE);
+    }
+
+    /**
+     * Sets a thumbnail bitmap for the current view and ensures the selection border and scrim is
+     * showing, if the image has already been selected.
+     * @param thumbnail The Bitmap to use for the icon ImageView.
+     * @return true if no image was loaded before (e.g. not even a low-res image).

[Theresa, 2017/03/28 20:40:28]

nit:s/true/True

[Finnur, 2017/03/31 14:26:50]

Done.

+     */
+    public boolean setThumbnailBitmap(Bitmap thumbnail) {
+        mIconView.setImageBitmap(thumbnail);
+
+        // If the tile has been selected before the bitmap has loaded, make sure it shows up with
+        // a selection border and scrim on load.
+        if (super.isChecked()) {
+            mIconView.getLayoutParams().height = mCategoryView.getImageSize() - 2 * mBorder;
+            mIconView.getLayoutParams().width = mCategoryView.getImageSize() - 2 * mBorder;

[Theresa, 2017/03/28 20:40:28]

nit: extract this calculation into a helper method.

[Finnur, 2017/03/31 14:26:50]

Done.

+            addPaddingToParent(mIconView, mBorder);
+            mScrim.setVisibility(View.VISIBLE);
+        }
+
+        boolean noImageWasLoaded = !mImageLoaded;
+        mImageLoaded = true;
+        updateSelectionState();
+
+        return noImageWasLoaded;
+    }
+
+    /**
+     * Initiates fading in of the thumbnail. Note, this should not be called if a grainy version of
+     * the thumbnail was loaded from cache. Otherwise a flash will appear.
+     */
+    public void fadeInThumbnail() {
+        mIconView.setAlpha(0.0f);
+        mIconView.animate().alpha(1.0f).setDuration(200).start();

[Theresa, 2017/03/28 20:40:28]

nit: define 200 as a constant somewhere.

[Finnur, 2017/03/31 14:26:50]

Done.

+    }
+
+    /**
+     * Resets the view to its starting state, which is necessary when the view is about to be
+     * re-used.
+     */
+    private void resetTile() {
+        mUnselectedView.setVisibility(View.GONE);
+        mSelectedView.setVisibility(View.GONE);
+        mScrim.setVisibility(View.GONE);
+        mSpecialTile.setVisibility(View.GONE);
+    }
+
+    /**
+     * Adds padding to the parent of the |view|.
+     * @param view The child view of the view to receive the padding.
+     * @param padding The amount of padding to use (in pixels).
+     */
+    private static void addPaddingToParent(View view, int padding) {
+        ViewGroup layout = (ViewGroup) view.getParent();
+        layout.setPadding(padding, padding, padding, padding);
+        layout.requestLayout();
+    }
+
+    /**
+     * Updates the selection controls for this view.
+     */
+    private void updateSelectionState() {
+        boolean special = mRequest.type() != PickerBitmap.TileTypes.PICTURE;
+        boolean checked = super.isChecked();
+        boolean anySelection =
+                mSelectionDelegate != null && mSelectionDelegate.isSelectionEnabled();
+        boolean multiSelect = mCategoryView.isMultiSelect();
+        int bgColorId, fgColorId;
+        if (!special) {
+            bgColorId = R.color.file_picker_tile_bg_color;
+            fgColorId = R.color.file_picker_special_tile_color;
+        } else if (!anySelection || !multiSelect) {
+            bgColorId = R.color.file_picker_special_tile_bg_color;
+            fgColorId = R.color.file_picker_special_tile_color;
+        } else {
+            bgColorId = R.color.file_picker_special_tile_disabled_bg_color;
+            fgColorId = R.color.file_picker_special_tile_disabled_color;
+        }
+
+        mBorderView.setBackgroundColor(ContextCompat.getColor(mContext, bgColorId));
+        mSpecialTile.setTextColor(ContextCompat.getColor(mContext, fgColorId));
+        Drawable[] drawables = mSpecialTile.getCompoundDrawables();
+        // The textview only has a top compound drawable (2nd element).
+        if (drawables[1] != null) {
+            int color = ContextCompat.getColor(mContext, fgColorId);
+            drawables[1].setColorFilter(color, PorterDuff.Mode.SRC_IN);
+        }
+
+        // The visibility of the unselected image is a little more complex because we don't want
+        // to show it when nothing is selected and also not on a blank canvas.
+        mSelectedView.setVisibility(!special && checked ? View.VISIBLE : View.GONE);
+        mUnselectedView.setVisibility(
+                !special && !checked && anySelection ? View.VISIBLE : View.GONE);
+        mScrim.setVisibility(!special && !checked && anySelection ? View.VISIBLE : View.GONE);
+    }
+}