Make TextViewWithClickableSpan activate only if you don't touch a link.

BUG=390226,418989,427087

Review URL: https://codereview.chromium.org/697183002

Cr-Commit-Position: refs/heads/master@{#303996}

ui/android/java/src/org/chromium/ui/widget/TextViewWithClickableSpans.java

@@ -5,22 +5,31 @@
 package org.chromium.ui.widget;
 
 import android.content.Context;
+import android.os.Bundle;
+import android.text.Layout;
 import android.text.SpannableString;
 import android.text.style.ClickableSpan;
 import android.util.AttributeSet;
 import android.view.Menu;
 import android.view.MenuItem;
+import android.view.MotionEvent;
 import android.view.View;
+import android.view.accessibility.AccessibilityManager;
+import android.view.accessibility.AccessibilityNodeInfo;
 import android.widget.PopupMenu;
 import android.widget.TextView;
 
 /**
- * ClickableSpan isn't accessible by default, so we create a simple subclass
- * of TextView that addresses this by adding click and longpress handlers.
- * If there's only one ClickableSpan, we activate it. If there's more than
- * one, we pop up a Spinner to disambiguate.
+ * ClickableSpan isn't accessible by default, so we create a subclass
+ * of TextView that tries to handle the case where a user clicks on a view
+ * and not directly on one of the clickable spans. We do nothing if it's a
+ * touch event directly on a ClickableSpan. Otherwise if there's only one
+ * ClickableSpan, we activate it. If there's more than one, we pop up a
+ * PopupMenu to disambiguate.
  */
 public class TextViewWithClickableSpans extends TextView {
+    private AccessibilityManager mAccessibilityManager;
+
     public TextViewWithClickableSpans(Context context) {
         super(context);
         init();
@@ -37,21 +46,74 @@ public TextViewWithClickableSpans(Context context, AttributeSet attrs, int defSt
     }
 
     private void init() {
-        setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                handleClick();
-            }
-        });
+        mAccessibilityManager = (AccessibilityManager)
+                getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
         setOnLongClickListener(new View.OnLongClickListener() {
             @Override
             public boolean onLongClick(View v) {
+                if (!mAccessibilityManager.isTouchExplorationEnabled()) {
+                    return false;
+                }
                 openDisambiguationMenu();
                 return true;
             }
         });
     }
 
+    @Override
+    public boolean performAccessibilityAction(int action, Bundle arguments) {
+        // BrailleBack will generate an accessibility click event directly
+        // on this view, make sure we handle that correctly.
+        if (action == AccessibilityNodeInfo.ACTION_CLICK) {
+            handleAccessibilityClick();
+            return true;
+        }
+        return super.performAccessibilityAction(action, arguments);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        boolean superResult = super.onTouchEvent(event);
+
+        if (event.getAction() != MotionEvent.ACTION_UP
+                && mAccessibilityManager.isTouchExplorationEnabled()
+                && !touchIntersectsAnyClickableSpans(event)) {
+            handleAccessibilityClick();
+            return true;
+        }
+
+        return superResult;
+    }
+
+    private boolean touchIntersectsAnyClickableSpans(MotionEvent event) {
+        // This logic is borrowed from android.text.method.LinkMovementMethod.
+        //
+        // ClickableSpan doesn't stop propagation of the event in its click handler,
+        // so we should only try to simplify clicking on a clickable span if the touch event
+        // isn't already over a clickable span.
+
+        CharSequence text = getText();
+        if (!(text instanceof SpannableString)) return false;
+        SpannableString spannable = (SpannableString) text;
+
+        int x = (int) event.getX();
+        int y = (int) event.getY();
+
+        x -= getTotalPaddingLeft();
+        y -= getTotalPaddingTop();
+
+        x += getScrollX();
+        y += getScrollY();
+
+        Layout layout = getLayout();
+        int line = layout.getLineForVertical(y);
+        int off = layout.getOffsetForHorizontal(line, x);
+
+        ClickableSpan[] clickableSpans =
+                spannable.getSpans(off, off, ClickableSpan.class);
+        return clickableSpans.length > 0;
+    }
+
     private ClickableSpan[] getClickableSpans() {
         CharSequence text = getText();
         if (!(text instanceof SpannableString)) return null;
@@ -60,7 +122,7 @@ private ClickableSpan[] getClickableSpans() {
         return spannable.getSpans(0, spannable.length(), ClickableSpan.class);
     }
 
-    private void handleClick() {
+    private void handleAccessibilityClick() {
         ClickableSpan[] clickableSpans = getClickableSpans();
         if (clickableSpans == null || clickableSpans.length == 0) {
             return;