Split the footer in ClearBrowsingDataPreferences into two paragraphs

chrome/android/java/src/org/chromium/chrome/browser/preferences/TextMessageWithLinkAndIconPreference.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/TextMessageWithLinkAndIconPreference.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/TextMessageWithLinkAndIconPreference.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/TextMessageWithLinkAndIconPreference.java
new file mode 100644
index 0000000000000000000000000000000000000000..7455322cc2801994e46ae1dcb5039c61b2fe5461
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/TextMessageWithLinkAndIconPreference.java
@@ -0,0 +1,82 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.

[newt (away), 2016/04/02 01:24:03]

2014?! ;)

[msramek, 2016/04/04 16:23:12]

Done. I guess I should write a presubmit check for this :)

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.preferences;
+
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import android.text.SpannableString;
+import android.text.TextPaint;
+import android.text.method.LinkMovementMethod;
+import android.text.style.ClickableSpan;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import org.chromium.chrome.R;
+import org.chromium.ui.text.SpanApplier;
+
+/**
+ * A text message whose summary can contain links.
+ */
+public class TextMessageWithLinkAndIconPreference extends TextMessagePreference {
+    private String mUrl;
+
+    /**
+     * Constructor for inflating from XML.
+     */
+    public TextMessageWithLinkAndIconPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        setLayoutResource(R.layout.text_message_with_link_and_icon_preference);
+    }
+
+    /**
+     * Sets the URL which should be opened after clicking on the link.
+     * @param url The URL to be opened.
+     */
+    public void setUrl(String url) {

[newt (away), 2016/04/02 01:24:03]

This method is fine, but just FYI, another option would be to use XML attributes
to specify the URL. For example, see the chrome:helpContext attribute on
LearnMorePreference.

[msramek, 2016/04/04 16:23:12]

Hmm, yes, I agree it's more elegant that way. But since you suggested below that
we should not hardcode here that the link opens a URL, I'll remove this part
altogether.

+        mUrl = url;
+    }
+
+    @Override
+    public void setSummary(CharSequence summary) {
+        // If there is no link in the summary, invoke the default behavior.
+        String summaryString = summary.toString();
+        if (!summaryString.contains("<link>") || !summaryString.contains("</link>")) {
+            super.setSummary(summary);
+            return;
+        }
+
+        // Linkify <link></link> span.
+        final SpannableString summaryWithLink = SpanApplier.applySpans(summaryString,

[newt (away), 2016/04/02 01:24:03]

Thought:

Putting the link opening logic inside this class doesn't feel quite right. It
constrains use of this class to cases where we want to open URLs in Chrome. Many
(most) links in Settings do something other than opening a URL, so this isn't
very general. Also, the API is a bit hidden: the text must contain
<link>...</link>, which isn't documented.

Maybe change this class to simply be TextMessageWithIconPreference, and allow
the user of the preference to add ClickableSpans to the summary text and handle
those clicks as they please. (This class still needs to support links by calling
TextView.setMovementMethod(), e.g., but otherwise can be hands-off.)

[msramek, 2016/04/04 16:23:12]

In ClearBrowsingDataPreferences, I have three instances of setSummary(), and I
wanted to avoid adding the boilerplate code with SpanApplier and ClickableSpan
everywhere by encapsulating it here.

As an alternative: I kept the <link></link> parsing logic here, and explained in
the class description how it works. Instead of directly opening an URL, I'm
passing in a Runnable ("setLinkClickDelegate") which can be used to execute an
arbitrary action; that action is then defined in ClearBrowsingData. This is more
flexible.

But if that still doesn't LGTY, I can follow your suggestion.

[newt (away), 2016/04/04 21:09:10]

This is fine with me :)  (I was envisioning that you'd add a method in
ClearBrowsingDataPreferences for creating and applying the ClickableSpan to the
summary text. But this solution is perfectly reasonable too.)

+                new SpanApplier.SpanInfo("<link>", "</link>", new ClickableSpan() {
+                    @Override
+                    public void onClick(View widget) {
+                        if (mUrl == null) return;
+
+                        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(mUrl));

[newt (away), 2016/04/02 01:24:03]

We want to ensure that this intent is opened in Chrome. You could explicitly set
the component/package/class (intent.setComponent(...)), or use

    new TabDelegate(false).launchUrl(url, tabLaunchType);

[msramek, 2016/04/04 16:23:12]

Done. Thanks! I didn't know about TabDelegate.

+                        intent.addCategory(Intent.CATEGORY_BROWSABLE);
+                        getContext().startActivity(intent);
+                    }
+                    // Change link formatting to use no underline
+                    @Override
+                    public void updateDrawState(TextPaint textPaint) {

[newt (away), 2016/04/02 01:24:03]

use NoUnderlineClickableSpan and you won't need this method

[msramek, 2016/04/04 16:23:12]

Done.

+                        textPaint.setColor(textPaint.linkColor);
+                        textPaint.setUnderlineText(false);
+                    }
+                }));
+
+        super.setSummary(summaryWithLink);
+    }
+
+    @Override
+    public View onCreateView(ViewGroup parent) {
+        View view = super.onCreateView(parent);
+        ((TextView) view.findViewById(android.R.id.summary)).setMovementMethod(
+                LinkMovementMethod.getInstance());
+        return view;
+    }
+}