xref: /packages/apps/Gallery2/src/com/android/gallery3d/filtershow/state/StatePanelTrack.java

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.gallery3d.filtershow.state;

import android.animation.LayoutTransition;
import android.content.Context;
import android.graphics.Point;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Adapter;
import android.widget.LinearLayout;
import com.android.gallery3d.filtershow.FilterShowActivity;
import com.android.gallery3d.filtershow.filters.FilterRepresentation;

public class StatePanelTrack extends LinearLayout implements PanelTrack {

    private static final String LOGTAG = "StatePanelTrack";
    private Point mTouchPoint;
    private StateView mCurrentView;
    private StateView mCurrentSelectedView;
    private boolean mExited = false;
    private boolean mStartedDrag = false;
    private StateAdapter mAdapter;
    private DragListener mDragListener = new DragListener(this);
    GestureDetector mGestureDetector;
    private int mContainerWidth = 668; // TODO: get this from XML
    private int mContainerHeight = 200;

    public StatePanelTrack(Context context, AttributeSet attrs) {
        super(context, attrs);
        GestureDetector.SimpleOnGestureListener simpleOnGestureListener
                = new GestureDetector.SimpleOnGestureListener(){
            @Override
            public void onLongPress(MotionEvent e) {
                longPress(e);
            }
            @Override
            public boolean onDoubleTap(MotionEvent e) {
                addDuplicate(e);
                return true;
            }
        };
        mGestureDetector = new GestureDetector(context, simpleOnGestureListener);
    }

    private void addDuplicate(MotionEvent e) {
        if (mCurrentSelectedView == null) {
            return;
        }
        int pos = findChild(mCurrentSelectedView);
        if (pos != -1) {
            mAdapter.insert(new State(mCurrentSelectedView.getState()), pos);
            fillContent(true);
        }
    }

    private void longPress(MotionEvent e) {
        View view = findChildAt((int) e.getX(), (int) e.getY());
        if (view == null) {
            return;
        }
        if (view instanceof StateView) {
            StateView stateView = (StateView) view;
            stateView.setDuplicateButton(true);
        }
    }

    public void setAdapter(StateAdapter adapter) {
        mAdapter = adapter;
        mAdapter.setListener(this);
        mAdapter.setOrientation(getOrientation());
        fillContent(false);
        requestLayout();
    }

    public StateView findChildWithState(State state) {
        for (int i = 0; i < getChildCount(); i++) {
            StateView view = (StateView) getChildAt(i);
            if (view.getState() == state) {
                return view;
            }
        }
        return null;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
        int w = MeasureSpec.getSize(widthMeasureSpec);
        if (w > 0) {
            mContainerWidth = w;
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        fillContent(false);
    }

    public void fillContent(boolean animate) {
        if (!animate) {
            this.setLayoutTransition(null);
        }
        int n = mAdapter.getCount();
        int w = mContainerWidth;
        int h = mContainerHeight;
        for (int i = 0; i < getChildCount(); i++) {
            StateView child = (StateView) getChildAt(i);
            child.resetPosition();
            if (!mAdapter.contains(child.getState())) {
                removeView(child);
            }
        }
        LayoutParams params;
        params = new LayoutParams(w, h);
        LayoutParams paramsEnds;
        paramsEnds = new LayoutParams(w, h/2);
        for (int i = 0; i < n; i++) {
            State s = mAdapter.getItem(i);
            if (findChildWithState(s) == null) {
                View view = mAdapter.getView(i, null, this);
                addView(view, i, params);
            }
        }
        for (int i = 0; i < n; i++) {
            State state = mAdapter.getItem(i);
            StateView view = (StateView) getChildAt(i);
            view.setState(state);
            if (i == 0) {
                view.setType(StateView.BEGIN);
            } else if (i == n - 1) {
                view.setType(StateView.END);
            }
            view.resetPosition();
            if (i == 0 || (i == n -1)) {
                if (view.getWidth() != w || view.getHeight() != h/2) {
                    view.setLayoutParams(paramsEnds);
                    requestLayout();
                }
            } else {
                if (view.getWidth() != w || view.getHeight() != h) {
                    view.setLayoutParams(params);
                    requestLayout();
                }
            }
        }

        if (!animate) {
            this.setLayoutTransition(new LayoutTransition());
        }
    }

    public void onTouch(MotionEvent event, StateView view) {
        if (!view.isDraggable()) {
            return;
        }
        mCurrentView = view;
        if (mCurrentSelectedView == mCurrentView) {
            return;
        }
        if (mCurrentSelectedView != null) {
            mCurrentSelectedView.setSelected(false);
        }
        // We changed the current view -- let's reset the
        // gesture detector.
        MotionEvent cancelEvent = MotionEvent.obtain(event);
        cancelEvent.setAction(MotionEvent.ACTION_CANCEL);
        mGestureDetector.onTouchEvent(cancelEvent);
        mCurrentSelectedView = mCurrentView;
        mCurrentSelectedView.setSelected(true);
        // We have to send the event to the gesture detector
        mGestureDetector.onTouchEvent(event);
        FilterShowActivity activity = (FilterShowActivity) getContext();
        activity.getPanelController().showComponentWithRepresentation(
                mCurrentSelectedView.getState().getFilterRepresentation());
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        if (mCurrentView != null) {
            return true;
        }
        return false;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (mCurrentView == null) {
            return false;
        }
        mGestureDetector.onTouchEvent(event);
        if (mTouchPoint == null) {
            mTouchPoint = new Point();
            mTouchPoint.x = (int) event.getX();
            mTouchPoint.y = (int) event.getY();
        }
        if (event.getActionMasked() == MotionEvent.ACTION_MOVE) {
            float translation = event.getY() - mTouchPoint.y;
            float alpha = 1.0f - (Math.abs(translation) / mCurrentView.getHeight());
            if (getOrientation() == LinearLayout.VERTICAL) {
                translation = event.getX() - mTouchPoint.x;
                alpha = 1.0f - (Math.abs(translation) / mCurrentView.getWidth());
                mCurrentView.setTranslationX(translation);
            } else {
                mCurrentView.setTranslationY(translation);
            }
            mCurrentView.setBackgroundAlpha(alpha);
            if (alpha < 0.7) {
                setOnDragListener(mDragListener);
                DragShadowBuilder shadowBuilder = new DragShadowBuilder(mCurrentView);
                mCurrentView.startDrag(null, shadowBuilder, mCurrentView, 0);
                mStartedDrag = true;
            }
        }
        if (event.getActionMasked() == MotionEvent.ACTION_UP
                || (!mStartedDrag && event.getActionMasked() == MotionEvent.ACTION_CANCEL)) {
            checkEndState();
        }
        return true;
    }

    public void checkEndState() {
        mTouchPoint = null;
        if (mExited || mCurrentView.getAlpha() < 0.2) {
            int origin = findChild(mCurrentView);
            if (origin != -1) {
                State current = mAdapter.getItem(origin);
                mAdapter.remove(current);
                fillContent(true);
            }
        } else {
            mCurrentView.setBackgroundAlpha(1.0f);
            mCurrentView.setTranslationX(0);
            mCurrentView.setTranslationY(0);
        }
        mCurrentView = null;
        mExited = false;
        mStartedDrag = false;
    }

    public View findChildAt(int x, int y) {
        Rect frame = new Rect();
        int scrolledXInt = getScrollX() + x;
        int scrolledYInt = getScrollY() + y;
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            child.getHitRect(frame);
            if (frame.contains(scrolledXInt, scrolledYInt)) {
                return child;
            }
        }
        return null;
    }

    public int findChild(View view) {
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            if (child == view) {
                return i;
            }
        }
        return -1;
    }

    public StateView getCurrentView() {
        return mCurrentView;
    }

    public void setCurrentView(View currentView) {
        mCurrentView = (StateView) currentView;
    }

    public void setExited(boolean value) {
        mExited = value;
    }

    public Point getTouchPoint() {
        return mTouchPoint;
    }

    public Adapter getAdapter() {
        return mAdapter;
    }
}