CB-8750 [wp8]: Allow resolution-specific splashscreen images

There are two aspect ratios for Windows Phone devices: 15:9 and 16:9. At
the moment, though, there is only one splash screen by default for WP8
Cordova apps. When stretched to fit all possible resolutions, this can
sometimes look bad.

WP supports resolution-specific splashscreens, so this commit adds the
same support to the splashscreen plugin. It uses the same base name for
the splashscreen, but adds modifiers such as ".screen-<res>" based on
the device. If a screen-specific image is found, it is used. If not, we
fall back to the single default image.

Fixes https://issues.apache.org/jira/browse/CB-8750

github close #41
github close #42

plugin.xml

@@ -98,6 +98,7 @@
         </config-file>
 
         <source-file src="src/wp/SplashScreen.cs" />
+        <source-file src="src/wp/ResolutionHelper.cs" />
 
     </platform>
 
@@ -111,6 +112,7 @@
         </config-file>
 
         <source-file src="src/wp/SplashScreen.cs" />
+        <source-file src="src/wp/ResolutionHelper.cs" />
 
     </platform>
 

src/wp/ResolutionHelper.cs

@@ -0,0 +1,60 @@
+/*
+    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.
+*/
+
+using Microsoft.Phone.Info;
+using System;
+using System.Windows;
+
+namespace WPCordovaClassLib.Cordova.Commands
+{
+    public enum Resolutions { WVGA, WXGA, HD };
+
+    public static class ResolutionHelper
+    {
+        private static bool IsWvga
+        {
+            get
+            {
+                return Application.Current.Host.Content.ScaleFactor == 100;
+            }
+        }
+
+        private static bool IsWxga
+        {
+            get
+            {
+                return Application.Current.Host.Content.ScaleFactor == 160;
+            }
+        }
+
+        private static bool IsHD
+        {
+            get
+            {
+                return Application.Current.Host.Content.ScaleFactor == 150;
+            }
+        }
+
+        public static Resolutions CurrentResolution
+        {
+            get
+            {
+                if (IsWvga) return Resolutions.WVGA;
+                else if (IsWxga) return Resolutions.WXGA;
+                else if (IsHD) return Resolutions.HD;
+                else throw new InvalidOperationException("Unknown resolution");
+            }
+        }
+    }
+}

src/wp/SplashScreen.cs

@@ -66,8 +66,7 @@ namespace WPCordovaClassLib.Cordova.Commands
                 Stretch = Stretch.Fill
             };
 
-            Uri imagePath = new Uri(prefImagePath, UriKind.RelativeOrAbsolute);
+            var imageResource = GetSplashScreenImageResource();
-            var imageResource = Application.GetResourceStream(imagePath);
             if (imageResource != null)
             {
                 BitmapImage splash_image = new BitmapImage();
@@ -133,6 +132,52 @@ namespace WPCordovaClassLib.Cordova.Commands
             }
         }
 
+        private StreamResourceInfo GetSplashScreenImageResource()
+        {
+            // Get the base filename for the splash screen images
+            string imageName = System.IO.Path.GetFileNameWithoutExtension(prefImagePath);
+            Uri imageUri = null;
+            StreamResourceInfo imageResource = null;
+
+            // First, try to get a resolution-specific splashscreen
+            try
+            {
+                // Determine the device's resolution
+                switch (ResolutionHelper.CurrentResolution)
+                {
+                    case Resolutions.HD:
+                        imageUri = new Uri(imageName + ".screen-720p.jpg", UriKind.Relative);
+                        break;
+
+                    case Resolutions.WVGA:
+                        imageUri = new Uri(imageName + ".screen-WVGA.jpg", UriKind.Relative);
+                        break;
+
+                    case Resolutions.WXGA:
+                    default:
+                        imageUri = new Uri(imageName + ".screen-WXGA.jpg", UriKind.Relative);
+                        break;
+                }
+
+                imageResource = Application.GetResourceStream(imageUri);
+            }
+            catch (Exception)
+            {
+                // It's OK if we didn't get a resolution-specific image
+            }
+
+            // Fallback to the default image name without decoration
+            if (imageResource == null)
+            {
+                imageUri = new Uri(prefImagePath, UriKind.Relative);
+                imageResource = Application.GetResourceStream(imageUri);
+            }
+
+            if (imageUri != null) Debug.WriteLine("INFO :: SplashScreen: using image {0}", imageUri.OriginalString);
+
+            return imageResource;
+        }
+
         public void show(string options = null)
         {
             Deployment.Current.Dispatcher.BeginInvoke(() =>