Improve UX for saving files (#801)

* Change default save dir, show warning if the project couldn't be saved
* Move safe save to project
* Closes #800

Author: SamCarlberg

core/src/main/java/edu/wpi/grip/core/serialization/Project.java

@@ -3,8 +3,10 @@
 import edu.wpi.grip.core.Pipeline;
 import edu.wpi.grip.core.PipelineRunner;
 import edu.wpi.grip.core.events.DirtiesSaveEvent;
+import edu.wpi.grip.core.events.WarningEvent;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
 import com.google.common.reflect.ClassPath;
 import com.thoughtworks.xstream.XStream;
@@ -36,6 +38,8 @@ public class Project {
 
   protected final XStream xstream = new XStream(new PureJavaReflectionProvider());
   @Inject
+  private EventBus eventBus;
+  @Inject
   private Pipeline pipeline;
   @Inject
   private PipelineRunner pipelineRunner;
@@ -120,6 +124,29 @@ void open(Reader reader) {
     saveIsDirty.set(false);
   }
 
+  /**
+   * Tries to save this project to the given file. Unlike {@link #save(File)}, this will <i>not</i>
+   * throw an IOException and will instead post a warning event to the event bus.
+   *
+   * @param file the file to save to
+   *
+   * @return true if the project was successfully saved to the given file, or false if the file
+   *              could not be written to
+   */
+  public boolean trySave(File file) {
+    try {
+      save(file);
+      return true;
+    } catch (IOException e) {
+      eventBus.post(new WarningEvent(
+          "Could not save project",
+          "The project could not be saved to " + file.getAbsolutePath()
+              + ".\n\nCause: " + e.getMessage()
+      ));
+      return false;
+    }
+  }
+
   /**
    * Save the project to a file.
    */

ui/src/main/java/edu/wpi/grip/ui/MainWindowController.java

@@ -1,5 +1,6 @@
 package edu.wpi.grip.ui;
 
+import edu.wpi.grip.core.GripFileManager;
 import edu.wpi.grip.core.Palette;
 import edu.wpi.grip.core.Pipeline;
 import edu.wpi.grip.core.PipelineRunner;
@@ -33,8 +34,6 @@
 import java.io.IOException;
 import java.util.Optional;
 import java.util.Set;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 import javafx.application.Platform;
 import javafx.fxml.FXML;
@@ -63,8 +62,6 @@
  */
 public class MainWindowController {
 
-  private static final Logger logger = Logger.getLogger(MainWindowController.class.getName());
-
   @FXML
   private Parent root;
   @FXML
@@ -154,11 +151,7 @@ private boolean showConfirmationDialogAndWait() {
       } else if (dialog.getResult().equals(save)) {
         // If the user chose "Save", automatically show a save dialog and block until the user
         // has had a chance to save the project.
-        try {
-          return saveProject();
-        } catch (IOException e) {
-          logger.log(Level.SEVERE, e.getMessage(), e.getCause());
-        }
+        return saveProject();
       }
     }
     return true;
@@ -219,11 +212,10 @@ public void openProject() {
    * @return true if the user does not cancel the save
    */
   @FXML
-  public boolean saveProject() throws IOException {
+  public boolean saveProject() {
     if (project.getFile().isPresent()) {
       // Immediately save the project to whatever file it was loaded from or last saved to.
-      project.save(project.getFile().get());
-      return true;
+      return project.trySave(project.getFile().get());
     } else {
       return saveProjectAs();
     }
@@ -237,10 +229,11 @@ public boolean saveProject() throws IOException {
    * @return true if the user does not cancel the save
    */
   @FXML
-  public boolean saveProjectAs() throws IOException {
+  public boolean saveProjectAs() {
     final FileChooser fileChooser = new FileChooser();
     fileChooser.setTitle("Save Project As");
     fileChooser.getExtensionFilters().add(new ExtensionFilter("GRIP File", "*.grip"));
+    fileChooser.setInitialDirectory(GripFileManager.GRIP_DIRECTORY);
 
     project.getFile().ifPresent(file -> fileChooser.setInitialDirectory(file.getParentFile()));
 
@@ -249,8 +242,7 @@ public boolean saveProjectAs() throws IOException {
       return false;
     }
 
-    project.save(file);
-    return true;
+    return project.trySave(file);
   }
 
   @FXML