add support for portable settings (resolves #360 and https://github.com/processing/processing/issues/3948)

Author: benfry

app/src/processing/app/Base.java

@@ -68,6 +68,13 @@ public class Base {
 
   static private boolean commandLine;
 
+  /**
+   * If settings.txt is present inside lib, it will be used to override
+   * the location of the settings folder so that "portable" versions
+   * of the software are possible.
+   */
+  static private File settingsOverride;
+
   // A single instance of the preferences window
   PreferencesFrame preferencesFrame;
 
@@ -158,6 +165,35 @@ static private void createAndShowGUI(String[] args) {
       }
     }
 
+    // Detect settings.txt in the lib folder for portable versions
+    File settingsFile = Platform.getContentFile("lib/settings.txt");
+    if (settingsFile != null && settingsFile.exists()) {
+      try {
+        Settings portable = new Settings(settingsFile);
+        String path = portable.get("settings.path");
+        File folder = new File(path);
+        boolean success = true;
+        if (!folder.exists()) {
+          success = folder.mkdirs();
+          if (!success) {
+            Messages.err("Could not create " + folder + " to store settings.");
+          }
+        }
+        if (success) {
+          if (!folder.canRead()) {
+            Messages.err("Cannot read from " + folder);
+          } else if (!folder.canWrite()) {
+            Messages.err("Cannot write to " + folder);
+          } else {
+            settingsOverride = folder.getAbsoluteFile();
+          }
+        }
+      } catch (IOException e) {
+        Messages.err("Error while reading the settings.txt file", e);
+      }
+    }
+
+
     Platform.init();
     // call after Platform.init() because we need the settings folder
     Console.startup();
@@ -1946,7 +1982,8 @@ static public InputStream getLibStream(String filename) throws IOException {
   /**
    * Get the directory that can store settings. (Library on OS X, App Data or
    * something similar on Windows, a dot folder on Linux.) Removed this as a
-   * preference for 3.0a3 because we need this to be stable.
+   * preference for 3.0a3 because we need this to be stable, but adding back
+   * for 4.0 beta 4 so that folks can do 'portable' versions again.
    */
   static public File getSettingsFolder() {
     File settingsFolder = null;
@@ -1973,6 +2010,11 @@ static public File getSettingsFolder() {
   }
 
 
+  static public File getSettingsOverride() {
+    return settingsOverride;
+  }
+
+
   /**
    * Convenience method to get a File object for the specified filename inside
    * the settings folder. Used to get preferences and recent sketch files.

app/src/processing/app/platform/DefaultPlatform.java

@@ -166,7 +166,13 @@ public void saveLanguage(String languageCode) { }
    * Do not return null.
    */
   public File getSettingsFolder() throws Exception {
-    // otherwise make a .processing directory int the user's home dir
+    File override = Base.getSettingsOverride();
+    if (override != null) {
+      return override;
+    }
+
+    // If no subclass has a behavior, default to making a
+    // ".processing" directory in the user's home directory.
     File home = new File(System.getProperty("user.home"));
     return new File(home, ".processing");
   }

app/src/processing/app/platform/LinuxPlatform.java

@@ -87,6 +87,11 @@ static public String getHomeDir(String user) throws Exception {
 
   @Override
   public File getSettingsFolder() throws Exception {
+    File override = Base.getSettingsOverride();
+    if (override != null) {
+      return override;
+    }
+
     // https://github.com/processing/processing4/issues/203
     // https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
 

app/src/processing/app/platform/MacPlatform.java

@@ -93,6 +93,10 @@ public void initBase(Base base) {
 
 
   public File getSettingsFolder() throws Exception {
+    File override = Base.getSettingsOverride();
+    if (override != null) {
+      return override;
+    }
     return new File(getLibraryFolder(), "Processing");
   }
 

app/src/processing/app/platform/WindowsPlatform.java

@@ -292,6 +292,11 @@ protected void checkPath() {
 
   // looking for Documents and Settings/blah/Application Data/Processing
   public File getSettingsFolder() throws Exception {
+    File override = Base.getSettingsOverride();
+    if (override != null) {
+      return override;
+    }
+
     try {
       String appDataRoaming = getAppDataPath();
       if (appDataRoaming != null) {

build/shared/lib/defaults.txt

@@ -77,9 +77,9 @@ recent.count = 10
 chooser.files.native = true
 # We were shutting this off on macOS because it broke Copy/Paste:
 # https://github.com/processing/processing/issues/1035
+# But removing again for 4.0 alpha 5, because the JFileChooser is awful,
+# and worse on Big Sur, so a bigger problem than the Copy/Paste issue.
 # https://github.com/processing/processing4/issues/77
-# But changing this for 4.0 alpha 5, because the JFileChooser is awful,
-# and even worse on Big Sur, and worse than the Copy/Paste issue.
 #chooser.files.native.macosx = false
 
 

todo.txt

@@ -21,6 +21,9 @@ X write release notes about not moving to RSyntaxArea
 X   https://github.com/processing/processing4/issues/355
 X   https://github.com/processing/processing/issues/3199
 X   https://github.com/processing/processing4/blob/master/app/src/processing/app/syntax/README.md
+X did we lose settings.path because it was too buggy?
+_   https://github.com/processing/processing/issues/3948
+_   https://github.com/processing/processing4/pull/360
 
 windows scaling
 X Fix "Could not delete disable_hidpi" message on macOS/Linux after closing prefs
@@ -355,8 +358,6 @@ _   already reported?
 teaching
 _ teacher wants user input on the console
 _   https://github.com/processing/processing/issues/5779
-_ did we lose settings.path because it was too buggy?
-_   https://github.com/processing/processing/issues/3948
 _ proxy trouble with p5? since adding the system proxy?
 _   https://github.com/processing/processing/pull/3251/files
 _   larger problem thread https://github.com/processing/processing/issues/3891