Add support for checking for assets when opening android app

forge-gui-mobile/src/forge/screens/SplashScreen.java

@@ -1,5 +1,10 @@
 package forge.screens;
 
+import java.io.File;
+import java.io.IOException;
+
+import com.badlogic.gdx.Application.ApplicationType;
+import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.graphics.g2d.TextureRegion;
 import com.badlogic.gdx.graphics.g2d.BitmapFont.HAlignment;
 
@@ -7,10 +12,14 @@ import forge.Forge.Graphics;
 import forge.assets.FSkin;
 import forge.assets.FSkinFont;
 import forge.assets.FSkinTexture;
+import forge.properties.ForgeConstants;
 import forge.properties.ForgePreferences;
 import forge.properties.ForgePreferences.FPref;
 import forge.toolbox.FContainer;
 import forge.toolbox.FProgressBar;
+import forge.util.BuildInfo;
+import forge.util.FileUtil;
+import forge.util.TextUtil;
 
 public class SplashScreen extends FContainer {
     private TextureRegion background;
@@ -21,6 +30,8 @@ public class SplashScreen extends FContainer {
         progressBar = new FProgressBar();
         progressBar.setDescription("Welcome to Forge");
 
+        checkForAssets();
+
         final ForgePreferences prefs = new ForgePreferences();
         FSkin.loadLight(prefs.getPref(FPref.UI_SKIN), this);
     }
@@ -75,4 +86,28 @@ public class SplashScreen extends FContainer {
         progressBar.setBounds(x + padding, y, w - 2 * padding, pbHeight);
         g.draw(progressBar);
     }
+
+    //if not forge-gui-mobile-dev, check whether assets are up to date
+    private void checkForAssets() {
+        if (Gdx.app.getType() == ApplicationType.Desktop) { return; }
+
+        String versionStr = BuildInfo.getVersionString();
+        File versionFile = new File(ForgeConstants.ASSETS_DIR + "version.txt");
+        if (!versionFile.exists()) {
+            try {
+                versionFile.createNewFile();
+            }
+            catch (IOException e) {
+                e.printStackTrace();
+                Gdx.app.exit(); //can't continue if this fails
+            }
+        }
+        else if (versionStr.equals(TextUtil.join(FileUtil.readFile(versionFile), "\n"))) {
+            return; //if version matches what had been previously saved, no need to download assets
+        }
+
+        //save version string to file once assets finish downloading
+        //so they don't need to be re-downloaded until you upgrade again
+        FileUtil.writeFile(versionFile, versionStr);
+    }
 }