🔍 Introduce default search engine dialog

chrome/android/java/src/org/chromium/chrome/browser/locale/DefaultSearchEnginePromoDialog.java

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// 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.locale;
+
+import android.content.Context;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.view.View;
+import android.widget.RadioButton;
+import android.widget.RadioGroup;
+import android.widget.RadioGroup.OnCheckedChangeListener;
+
+import org.chromium.base.library_loader.LibraryLoader;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.infobar.InfoBarControlLayout;
+import org.chromium.chrome.browser.search_engines.TemplateUrlService;
+import org.chromium.chrome.browser.search_engines.TemplateUrlService.TemplateUrl;
+import org.chromium.chrome.browser.widget.PromoDialog;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+/** A dialog that forces the user to choose a default search engine. */
+public class DefaultSearchEnginePromoDialog extends PromoDialog implements OnCheckedChangeListener {
+    /** Used to determine the promo dialog contents. */
+    private final int mDialogType;
+
+    /** Run when the dialog is dismissed after the user has chosen a search engine. */
+    private final Runnable mOnDismissed;
+
+    private RadioGroup mRadioGroup;
+    private String mSelectedKeyword;
+
+    /**
+     * Construct and show the dialog.  Will be asynchronous if the TemplateUrlService has not yet
+     * been loaded.
+     */
+    public static void create(

[Ted C, 2017/04/26 20:21:52]

maybe this should be called show?

[gone, 2017/04/26 21:45:15]

Done.

+            final Context context, final int dialogType, @Nullable final Runnable onDismissed) {

[Ted C, 2017/04/26 20:21:52]

Should/can dialogType have an associated IntDef?

Looks like onDismissed is more like onSuccess or onSearchEngineSelected

[gone, 2017/04/26 21:45:15]

Seems like it'd be fine to move it to always be called.  Moved it over.

+        assert LibraryLoader.isInitialized();
+
+        // Load up the search engines.
+        final TemplateUrlService instance = TemplateUrlService.getInstance();
+        instance.registerLoadListener(new TemplateUrlService.LoadListener() {
+            @Override
+            public void onTemplateUrlServiceLoaded() {
+                instance.unregisterLoadListener(this);
+                new DefaultSearchEnginePromoDialog(context, dialogType, onDismissed).show();
+            }
+        });
+        instance.load();
+    }
+
+    private DefaultSearchEnginePromoDialog(
+            Context context, int dialogType, @Nullable Runnable onDismissed) {
+        super(context);
+        mDialogType = dialogType;
+        mOnDismissed = onDismissed;
+        setOnDismissListener(this);
+
+        // No one should be able to bypass this dialog by clicking outside or by hitting back.
+        setCancelable(false);
+        setCanceledOnTouchOutside(false);
+    }
+
+    @Override
+    protected DialogParams getDialogParams() {
+        PromoDialog.DialogParams params = new PromoDialog.DialogParams();
+        params.headerStringResource = R.string.search_engine_dialog_title;
+        params.footerStringResource = R.string.search_engine_dialog_footer;
+        params.primaryButtonStringResource = R.string.ok;
+        return params;
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        assert LibraryLoader.isInitialized();

[Ted C, 2017/04/26 20:21:52]

Since this happens in the one place you create it above, I think this one
probably isn't necessary IMO

[gone, 2017/04/26 21:45:15]

Done.

+
+        // Set up the general UI.
+        InfoBarControlLayout controls = addControlLayout();
+        updateButtonState();
+
+        // Load up the search engines.
+        TemplateUrlService instance = TemplateUrlService.getInstance();
+        assert instance.isLoaded();
+        List<TemplateUrl> engines = null;
+        if (mDialogType == LocaleManager.SEARCH_ENGINE_PROMO_SHOW_EXISTING) {
+            engines = instance.getSearchEngines();
+        } else {
+            // TODO(dfalcantara): Handle the new user case.
+            assert false;
+        }
+
+        List<CharSequence> engineNames = new ArrayList<>();
+        List<String> engineKeywords = new ArrayList<>();
+        shuffleEngines(engines, engineNames, engineKeywords);
+
+        // Add the search engines to the dialog.
+        mRadioGroup = controls.addRadioButtons(
+                engineNames, engineKeywords, InfoBarControlLayout.INVALID_INDEX);
+        mRadioGroup.setOnCheckedChangeListener(this);
+    }
+
+    @Override
+    public void onCheckedChanged(RadioGroup group, int checkedId) {
+        mSelectedKeyword = null;
+
+        // Run through the RadioGroup to figure out which one was checked.
+        for (int i = 0; i < group.getChildCount(); i++) {
+            View child = group.getChildAt(i);
+            assert child instanceof RadioButton;
+
+            RadioButton button = (RadioButton) child;
+            if (button.isChecked()) {
+                assert mSelectedKeyword == null;
+                mSelectedKeyword = (String) button.getTag();
+            }
+        }
+
+        updateButtonState();
+    }
+
+    @Override
+    public void onClick(View view) {
+        if (view.getId() == R.id.button_primary) {
+            if (mSelectedKeyword == null) {
+                updateButtonState();
+                return;
+            }
+
+            dismiss();
+        } else {
+            assert false : "Unhandled click.";
+        }
+
+        // Don't propagate the click to the parent to prevent circumventing the dialog.
+    }
+
+    @Override
+    public void onDismiss(DialogInterface dialog) {
+        if (mSelectedKeyword == null) {
+            // This shouldn't happen, but in case it does, finish the Activity so that the user has
+            // to respond to the dialog next time.
+            if (getOwnerActivity() != null) getOwnerActivity().finish();

[Ted C, 2017/04/26 20:21:52]

should this be finish and remove task?

[gone, 2017/04/26 21:45:15]

I'd argue for a regular finish() so that the activity stays findable in recents
(if it normally is).

+        } else {
+            TemplateUrlService.getInstance().setSearchEngine(mSelectedKeyword.toString());
+            if (mOnDismissed != null) mOnDismissed.run();
+            // TODO(dfalcantara): Prevent the dialog from appearing again.
+        }
+    }
+
+    private void updateButtonState() {
+        findViewById(R.id.button_primary).setEnabled(mSelectedKeyword != null);
+    }
+
+    private void shuffleEngines(
+            List<TemplateUrl> engines, List<CharSequence> names, List<String> keywords) {
+        ArrayList<Integer> indices = new ArrayList<>();

[Ted C, 2017/04/26 20:21:52]

Could we use:
https://developer.android.com/reference/java/util/Collections.html#shuffle(ja...,
java.util.Random)

[gone, 2017/04/26 21:45:15]

Works for me.

+        for (int i = 0; i < engines.size(); i++) indices.add(i);
+
+        Random generator = new Random();
+        for (int i = 0; i < indices.size(); i++) {
+            int remaining = indices.size() - i;
+            int shuffleIndex = i + generator.nextInt(remaining);
+
+            if (shuffleIndex != i) {
+                int temp = indices.get(i);
+                indices.set(i, indices.get(shuffleIndex));
+                indices.set(shuffleIndex, temp);
+            }
+        }
+
+        for (Integer index : indices) {
+            TemplateUrl engine = engines.get(index);
+            names.add(engine.getShortName());
+            keywords.add(engine.getKeyword());
+        }
+    }
+}