/*
 * Copyright (C) 2016 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.setupwizardlib.span;

import android.content.Context;
import android.graphics.Typeface;
import android.os.Build;
import android.text.TextPaint;
import android.text.style.ClickableSpan;
import android.util.Log;
import android.view.View;

/**
 * A clickable span that will listen for click events and send it back to the context. To use this
 * class, implement {@link com.android.setupwizardlib.span.LinkSpan.OnClickListener} in your
 * context (typically your Activity).
 *
 * <p />Note on accessibility: For TalkBack to be able to traverse and interact with the links, you
 * should use {@code LinkAccessibilityHelper} in your {@code TextView} subclass. Optionally you can
 * also use {@code RichTextView}, which includes link support.
 */
public class LinkSpan extends ClickableSpan {

    /*
     * Implementation note: When the orientation changes, TextView retains a reference to this span
     * instead of writing it to a parcel (ClickableSpan is not Parcelable). If this class has any
     * reference to the containing Activity (i.e. the activity context, or any views in the
     * activity), it will cause memory leak.
     */

    /* static section */

    private static final String TAG = "LinkSpan";

    private static final Typeface TYPEFACE_MEDIUM =
            Typeface.create("sans-serif-medium", Typeface.NORMAL);

    public interface OnClickListener {
        void onClick(LinkSpan span);
    }

    /* non-static section */

    private final String mId;

    public LinkSpan(String id) {
        mId = id;
    }

    @Override
    public void onClick(View view) {
        final Context context = view.getContext();
        if (context instanceof OnClickListener) {
            ((OnClickListener) context).onClick(this);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                view.cancelPendingInputEvents();
            }
        } else {
            Log.w(TAG, "Dropping click event. No listener attached.");
        }
    }

    @Override
    public void updateDrawState(TextPaint drawState) {
        super.updateDrawState(drawState);
        drawState.setUnderlineText(false);
        drawState.setTypeface(TYPEFACE_MEDIUM);
    }

    public String getId() {
        return mId;
    }
}