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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.setupwizardlib.span;
     18 
     19 import android.content.Context;
     20 import android.graphics.Typeface;
     21 import android.os.Build;
     22 import android.text.TextPaint;
     23 import android.text.style.ClickableSpan;
     24 import android.util.Log;
     25 import android.view.View;
     26 
     27 /**
     28  * A clickable span that will listen for click events and send it back to the context. To use this
     29  * class, implement {@link com.android.setupwizardlib.span.LinkSpan.OnClickListener} in your
     30  * context (typically your Activity).
     31  *
     32  * <p />Note on accessibility: For TalkBack to be able to traverse and interact with the links, you
     33  * should use {@code LinkAccessibilityHelper} in your {@code TextView} subclass. Optionally you can
     34  * also use {@code RichTextView}, which includes link support.
     35  */
     36 public class LinkSpan extends ClickableSpan {
     37 
     38     /*
     39      * Implementation note: When the orientation changes, TextView retains a reference to this span
     40      * instead of writing it to a parcel (ClickableSpan is not Parcelable). If this class has any
     41      * reference to the containing Activity (i.e. the activity context, or any views in the
     42      * activity), it will cause memory leak.
     43      */
     44 
     45     /* static section */
     46 
     47     private static final String TAG = "LinkSpan";
     48 
     49     private static final Typeface TYPEFACE_MEDIUM =
     50             Typeface.create("sans-serif-medium", Typeface.NORMAL);
     51 
     52     public interface OnClickListener {
     53         void onClick(LinkSpan span);
     54     }
     55 
     56     /* non-static section */
     57 
     58     private final String mId;
     59 
     60     public LinkSpan(String id) {
     61         mId = id;
     62     }
     63 
     64     @Override
     65     public void onClick(View view) {
     66         final Context context = view.getContext();
     67         if (context instanceof OnClickListener) {
     68             ((OnClickListener) context).onClick(this);
     69             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
     70                 view.cancelPendingInputEvents();
     71             }
     72         } else {
     73             Log.w(TAG, "Dropping click event. No listener attached.");
     74         }
     75     }
     76 
     77     @Override
     78     public void updateDrawState(TextPaint drawState) {
     79         super.updateDrawState(drawState);
     80         drawState.setUnderlineText(false);
     81         drawState.setTypeface(TYPEFACE_MEDIUM);
     82     }
     83 
     84     public String getId() {
     85         return mId;
     86     }
     87 }
     88