Create the customized TabLayout for the new translate UI

chrome/android/java/src/org/chromium/chrome/browser/infobar/translate/TranslateTabLayout.java

Index: chrome/android/java/src/org/chromium/chrome/browser/infobar/translate/TranslateTabLayout.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/infobar/translate/TranslateTabLayout.java b/chrome/android/java/src/org/chromium/chrome/browser/infobar/translate/TranslateTabLayout.java
index eb684d4eb786c97cae58d79318566777289698d1..f09f409334ce1b551629113425b60960defc83b3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/infobar/translate/TranslateTabLayout.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/infobar/translate/TranslateTabLayout.java
@@ -5,20 +5,169 @@
 package org.chromium.chrome.browser.infobar.translate;
 
 import android.content.Context;
+import android.support.annotation.NonNull;
 import android.support.design.widget.TabLayout;
 import android.util.AttributeSet;
+import android.view.LayoutInflater;
+import android.view.MotionEvent;
+
+import org.chromium.chrome.R;
 
 /**
- * Lays out an infobar that has all of its controls along a line.
- * It's currently used for Translate UI redesign only.
+ * TabLayout shown in the TranslateCompactInfoBar.
  */
 public class TranslateTabLayout extends TabLayout {
+    // The tab in which a spinning progress bar is showing.
+    private Tab mTabShowingProgressBar = null;
+
+    private Context mContext;

[gone, 2017/03/29 17:04:10]

Can these be final?

[Marti Wong, 2017/03/29 23:38:07]

Done. Yes, it can be final :)

+    private AttributeSet mAttrs;
+    private int mDefStyleAttr;

[Marti Wong, 2017/03/29 23:38:07]

mAttrs and mDefStyleAttr no longer needed after setting textAppearance in XML

+
     /**
      * Constructor for inflating from XML.
      */
     public TranslateTabLayout(Context context, AttributeSet attrs) {
-        super(context, attrs);
+        this(context, attrs, 0);
+    }
+
+    public TranslateTabLayout(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+
+        mAttrs = attrs;
+        mDefStyleAttr = defStyleAttr;
+        mContext = context;
+    }
+
+    /**
+     * Add new Tabs with title strings.
+     * @param titles Titles of the tabs to be added.
+     */
+    public void addTabs(CharSequence... titles) {
+        for (CharSequence title : titles) {
+            addTabWithTitle(title);
+        }
+    }
+
+    /**
+     * Add a new Tab with the title string.
+     * @param tabTitle Title string of the new tab.
+     */
+    public void addTabWithTitle(CharSequence tabTitle) {
+        TranslateTabContent tabContent =
+                (TranslateTabContent) LayoutInflater.from(mContext).inflate(
+                        R.layout.infobar_translate_tab_content, this, false);
+        tabContent.setupTextAppearance(mContext, getTabTextColors(), mAttrs, mDefStyleAttr);
+        tabContent.setText(tabTitle);
+
+        Tab tab = newTab();
+        tab.setCustomView(tabContent);
+        tab.setContentDescription(tabTitle);
+        super.addTab(tab);
+    }
+
+    /**
+     * Replace the title string of a tab.
+     * @param tabPos   The position of the tab to modify.
+     * @param tabTitle The new title string.
+     */
+    public void replaceTabTitle(int tabPos, CharSequence tabTitle) {
+        if (tabPos < 0 || tabPos >= getTabCount()) {
+            return;
+        }
+        Tab tab = getTabAt(tabPos);
+        ((TranslateTabContent) tab.getCustomView()).setText(tabTitle);
+        tab.setContentDescription(tabTitle);
+    }
+
+    /**
+     * Select a tab.
+     * @param tabPos The position of the tab to select.
+     */
+    public void selectTab(int tabPos) {
+        if (tabPos < 0 || tabPos >= getTabCount() || mTabShowingProgressBar != null) {
+            return;
+        }
+        getTabAt(tabPos).select();
+    }
+
+    /**
+     * Show the spinning progress bar on a specified tab.
+     * @param tabPos The position of the tab to show the progress bar.
+     */
+    public void showProgressBarOnTab(int tabPos) {
+        if (tabPos < 0 || tabPos >= getTabCount()) {
+            return;
+        }
+        if (mTabShowingProgressBar != null) {

[gone, 2017/03/29 17:04:10]

Might as well combine this with the above conditional like you do for selectTab.

[Marti Wong, 2017/03/29 23:38:07]

Done.

+            return;
+        }
+        mTabShowingProgressBar = getTabAt(tabPos);
+
+        mTabShowingProgressBar.select();
+
+        // TODO(martiw) See if we need to setContentDescription as "Translating" here.
+
+        if (tabIsSupported(mTabShowingProgressBar)) {
+            ((TranslateTabContent) mTabShowingProgressBar.getCustomView()).showProgressBar();
+        }
+    }
+
+    /** Stop the spinning progress bar. */
+    public void stopProgressBarAndRevertBack() {
+        if (mTabShowingProgressBar == null) {
+            return;
+        }
+
+        // TODO(martiw) if we have setContentDescription at showProgressBarOnTab(), we need to
+        // revert it here.
+
+        if (tabIsSupported(mTabShowingProgressBar)) {
+            ((TranslateTabContent) mTabShowingProgressBar.getCustomView()).hideProgressBar();
+        }
+        // TODO(martiw) See if we need to prevent the following from triggering onTabSelected event.
+        selectTab(0); // switch the selection back to the first tab.
+
+        mTabShowingProgressBar = null;
+    }
+
+    // Overrided to block children's touch event when showing progress bar.
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        // Allow touches to propagate to children only if the layout can be interacted with.
+        if (mTabShowingProgressBar != null) {
+            return true;
+        }
+        return super.onInterceptTouchEvent(ev);
+    }
+
+    /** Check if the tab is supported in TranslateTabLayout. */
+    private boolean tabIsSupported(Tab tab) {
+        return (tab.getCustomView() != null && tab.getCustomView() instanceof TranslateTabContent);

[gone, 2017/03/29 17:04:10]

you don't need to null check; instanceof automatically returns false if
tab.getCustomView() is null.

[Marti Wong, 2017/03/29 23:38:07]

Done.

     }
 
-    // TODO(martiw): Add special methods on demand.
+    // Overrided to make sure only supported Tabs can be added.
+    @Override
+    public void addTab(@NonNull Tab tab, int position, boolean setSelected) {
+        if (!tabIsSupported(tab)) {
+            throwsIllegalArgumentException();
+            return;
+        }
+        super.addTab(tab, position, setSelected);
+    }
+
+    // Overrided to make sure only supported Tabs can be added.
+    @Override
+    public void addTab(@NonNull Tab tab, boolean setSelected) {
+        if (!tabIsSupported(tab)) {
+            throwsIllegalArgumentException();
+            return;
+        }
+        super.addTab(tab, setSelected);
+    }
+
+    private void throwsIllegalArgumentException() {
+        throw new IllegalArgumentException(

[gone, 2017/03/29 17:04:10]

Ah, I meant that you could probably just inline this instead of making a
function for it.  You don't really need a custom message because it'll be
obvious what went wrong if it gets thrown.  Up to you, though.

[Marti Wong, 2017/03/29 23:38:07]

Done.
Agree, it can make the code cleaner.
I removed the "return" after throwing IllegalArgumentException() as well.

+                "Only Tab with TranslateTabContent as its CustomView is allowed to add.");

[gone, 2017/03/29 17:04:11]

is allowed to add -> can be added

[Marti Wong, 2017/03/29 23:38:07]

Message removed.

+    }
 }