com.manuelpeinado.fadingactionbar.FadingActionBarHelper Maven / Gradle / Ivy

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package com.manuelpeinado.fadingactionbar;

import android.app.Activity;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.FrameLayout;
import android.widget.ListView;
import android.widget.ScrollView;

import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.SherlockActivity;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.actionbarsherlock.app.SherlockListActivity;
import com.cyrilmottier.android.translucentactionbar.NotifyingScrollView;

public class FadingActionBarHelper {
    private Drawable mActionBarBackgroundDrawable;
    private FrameLayout mHeaderContainer;
    private int mActionBarBackgroundResId;
    private int mHeaderLayoutResId;
    private View mHeaderView;
    private int mContentLayoutResId;
    private View mContentView;
    private ActionBar mActionBar;
    private LayoutInflater mInflater;
    private boolean mLightActionBar;

    public FadingActionBarHelper actionBarBackground(int drawableResId) {
        mActionBarBackgroundResId = drawableResId;
        return this;
    }

    public FadingActionBarHelper actionBarBackground(Drawable drawable) {
        mActionBarBackgroundDrawable = drawable;
        return this;
    }

    public FadingActionBarHelper headerLayout(int layoutResId) {
        mHeaderLayoutResId = layoutResId;
        return this;
    }

    public FadingActionBarHelper headerView(View view) {
        mHeaderView = view;
        return this;
    }

    public FadingActionBarHelper contentLayout(int layoutResId) {
        mContentLayoutResId = layoutResId;
        return this;
    }

    public FadingActionBarHelper contentView(View view) {
        mContentView = view;
        return this;
    }

    public FadingActionBarHelper lightActionBar(boolean value) {
        mLightActionBar = value;
        return this;
    }

    public View createView(Context context) {
        return createView(LayoutInflater.from(context));
    }

    public View createView(LayoutInflater inflater) {
        //
        // Prepare everything

        mInflater = inflater;
        if (mContentView == null) {
            mContentView = inflater.inflate(mContentLayoutResId, null);
        }
        if (mHeaderView == null) {
            mHeaderView = inflater.inflate(mHeaderLayoutResId, mHeaderContainer, false);
        }

        //
        // See if we are in a ListView or ScrollView scenario

        ListView listView = (ListView) mContentView.findViewById(android.R.id.list);
        if (listView != null) {
            return createListView(listView);
        }
        return createScrollView();
    }

    public void initActionBar(Activity activity) {
        mActionBar = getActionBar(activity);
        if (mActionBarBackgroundDrawable == null) {
            mActionBarBackgroundDrawable = activity.getResources().getDrawable(mActionBarBackgroundResId);
        }
        mActionBar.setBackgroundDrawable(mActionBarBackgroundDrawable);
        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.JELLY_BEAN) {
            mActionBarBackgroundDrawable.setCallback(mDrawableCallback);
        }
        mActionBarBackgroundDrawable.setAlpha(0);
    }

    private ActionBar getActionBar(Activity activity) {
        if (activity instanceof SherlockActivity) {
            return ((SherlockActivity)activity).getSupportActionBar();
        }
        if (activity instanceof SherlockFragmentActivity) {
            return ((SherlockFragmentActivity)activity).getSupportActionBar();
        }
        if (activity instanceof SherlockListActivity) {
            return ((SherlockListActivity)activity).getSupportActionBar();
        }
        throw new RuntimeException("Activity should derive from one of the ActionBarSherlock");
    }

    private Drawable.Callback mDrawableCallback = new Drawable.Callback() {
        @Override
        public void invalidateDrawable(Drawable who) {
            mActionBar.setBackgroundDrawable(who);
        }

        @Override
        public void scheduleDrawable(Drawable who, Runnable what, long when) {
        }

        @Override
        public void unscheduleDrawable(Drawable who, Runnable what) {
        }
    };

    private View createScrollView() {
        ViewGroup scrollViewContainer = (ViewGroup) mInflater.inflate(R.layout.fab__scrollview_container, null);

        NotifyingScrollView scrollView = (NotifyingScrollView) scrollViewContainer.findViewById(R.id.fab__scroll_view);
        scrollView.setOnScrollChangedListener(mOnScrollChangedListener);

        ViewGroup container = (ViewGroup) scrollViewContainer.findViewById(R.id.fab__container);
        container.addView(mContentView);
        mHeaderContainer = (FrameLayout) scrollViewContainer.findViewById(R.id.fab__header_container);
        initializeGradient(mHeaderContainer);
        mHeaderContainer.addView(mHeaderView, 0);
        
        return scrollViewContainer;
    }

    private NotifyingScrollView.OnScrollChangedListener mOnScrollChangedListener = new NotifyingScrollView.OnScrollChangedListener() {
        public void onScrollChanged(ScrollView who, int l, int t, int oldl, int oldt) {
            onNewScroll(t);
        }
    };

    private View createListView(ListView listView) {
        mHeaderContainer = (FrameLayout) mInflater.inflate(R.layout.fab__header_container, null);
        initializeGradient(mHeaderContainer);
        mHeaderContainer.addView(mHeaderView, 0);
        listView.addHeaderView(mHeaderContainer, null, false);

        listView.setOnScrollListener(mOnScrollListener);
        
        return mContentView;
    }

    private OnScrollListener mOnScrollListener = new OnScrollListener() {
        @Override
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
            View topChild = view.getChildAt(0);
            if (topChild == null) {
                onNewScroll(0);
            } else if (topChild != mHeaderContainer) {
                onNewScroll(mHeaderContainer.getHeight());
            } else {
                onNewScroll(-topChild.getTop());
            }
        }

        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
        }
    };

    private void onNewScroll(int scrollPosition) {
        if (mActionBar == null) {
            return;
        }
        int headerHeight = mHeaderContainer.getHeight() - mActionBar.getHeight();
        float ratio = (float) Math.min(Math.max(scrollPosition, 0), headerHeight) / headerHeight;
        int newAlpha = (int) (ratio * 255);
        mActionBarBackgroundDrawable.setAlpha(newAlpha);
    }

    private void initializeGradient(ViewGroup headerContainer) {
        View gradientView = headerContainer.findViewById(R.id.fab__gradient);
        int gradient = R.drawable.fab__gradient;
        if (mLightActionBar) {
            gradient = R.drawable.fab__gradient_light;
        }
        gradientView.setBackgroundResource(gradient);
    }
}