Require double confirmation for deleting a book

The user must check a checkbox to enable the delete button. This tries
to avoid confirming irreversible actions by mistake.

Fixes #544

app/src/main/java/org/gnucash/android/ui/settings/BookManagerFragment.java

@@ -38,6 +38,8 @@
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.CheckBox;
+import android.widget.CompoundButton;
 import android.widget.EditText;
 import android.widget.ImageView;
 import android.widget.ListView;
@@ -199,30 +201,8 @@ public boolean onMenuItemClick(MenuItem item) {
                                 case R.id.ctx_menu_sync_book:
                                     //TODO implement sync
                                     return false;
-                                case R.id.ctx_menu_delete_book: {
-                                    AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(getActivity());
-                                    dialogBuilder.setTitle(getString(R.string.title_confirm_delete_book))
-                                            .setIcon(R.drawable.ic_close_black_24dp)
-                                            .setMessage(getString(R.string.msg_all_book_data_will_be_deleted));
-                                    dialogBuilder.setPositiveButton(getString(R.string.btn_delete_book), new DialogInterface.OnClickListener() {
-                                        @Override
-                                        public void onClick(DialogInterface dialog, int which) {
-                                            BooksDbAdapter.getInstance().deleteBook(bookUID);
-                                            refresh();
-                                        }
-                                    });
-                                    dialogBuilder.setNegativeButton(R.string.btn_cancel, new DialogInterface.OnClickListener() {
-                                        @Override
-                                        public void onClick(DialogInterface dialog, int which) {
-                                            dialog.dismiss();
-                                        }
-                                    });
-                                    AlertDialog dialog = dialogBuilder.create();
-                                    dialog.show(); //must be called before you can access buttons
-                                    dialog.getButton(AlertDialog.BUTTON_POSITIVE)
-                                            .setTextColor(ContextCompat.getColor(context, R.color.account_red));
-                                }
-                                return true;
+                                case R.id.ctx_menu_delete_book:
+                                    return handleMenuDeleteBook(bookUID);
                                 default:
                                     return true;
                             }
@@ -238,6 +218,38 @@ public void onClick(DialogInterface dialog, int which) {
             });
         }
 
+        private boolean handleMenuDeleteBook(final String bookUID) {
+            AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(getActivity());
+            dialogBuilder.setTitle(getString(R.string.title_confirm_delete_book))
+                    .setIcon(R.drawable.ic_close_black_24dp)
+                    .setView(R.layout.dialog_double_confirm)
+                    .setMessage(getString(R.string.msg_all_book_data_will_be_deleted));
+            dialogBuilder.setPositiveButton(getString(R.string.btn_delete_book), new DialogInterface.OnClickListener() {
+                @Override
+                public void onClick(DialogInterface dialog, int which) {
+                    BooksDbAdapter.getInstance().deleteBook(bookUID);
+                    refresh();
+                }
+            });
+            dialogBuilder.setNegativeButton(R.string.btn_cancel, new DialogInterface.OnClickListener() {
+                @Override
+                public void onClick(DialogInterface dialog, int which) {
+                    dialog.dismiss();
+                }
+            });
+            final AlertDialog dialog = dialogBuilder.create();
+            dialog.show(); //must be called before you can access buttons
+            dialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);
+            CheckBox confirmCheckBox = dialog.findViewById(R.id.checkbox_confirm);
+            confirmCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+                @Override
+                public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
+                    dialog.getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(b);
+                }
+            });
+            return true;
+        }
+
         /**
          * Opens a dialog for renaming a book
          * @param bookName Current name of the book

app/src/main/res/layout/dialog_double_confirm.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+ Copyright (c) 2017 Ngewi Fet <ngewif@gmail.com>
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+              xmlns:tools="http://schemas.android.com/tools"
+              android:layout_width="match_parent"
+              android:layout_height="wrap_content"
+              android:orientation="vertical"
+              android:padding="@dimen/dialog_padding" >
+
+    <CheckBox
+        android:id="@+id/checkbox_confirm"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/yes_sure"/>
+</LinearLayout>

app/src/main/res/values/strings.xml

@@ -462,4 +462,5 @@
     <string name="label_select_destination_after_export">Select the destination after export is complete</string>
     <string name="label_dropbox_export_destination">Export to \'/Apps/GnuCash Android/\' folder on Dropbox</string>
     <string name="title_section_preferences">Preferences</string>
+    <string name="yes_sure">Yes, I\'m sure</string>
 </resources>