Moved source into separate src directory due to popular request

[GpsPrune.git] / src / tim / prune / FileDropHandler.java

diff --git a/src/tim/prune/FileDropHandler.java b/src/tim/prune/FileDropHandler.java
new file mode 100644 (file)
index 0000000..2c76385
--- /dev/null
+++ b/src/tim/prune/FileDropHandler.java
@@ -0,0 +1,158 @@
+package tim.prune;
+
+import java.awt.datatransfer.DataFlavor;
+import java.io.File;
+import java.net.URI;
+import java.util.ArrayList;
+
+import javax.swing.TransferHandler;
+
+/**
+ * Class to listen for drag/drop events and react to dropping files on to the application
+ */
+public class FileDropHandler extends TransferHandler
+{
+       /** App object for passing results back to */
+       private App _app = null;
+
+       /** Fixed flavour in case the java file list flavour isn't available */
+       private static DataFlavor _uriListFlavour = null;
+
+       /** Static block to initialise the list flavour */
+       static
+       {
+               try {_uriListFlavour = new DataFlavor("text/uri-list;class=java.lang.String");
+               } catch (ClassNotFoundException nfe) {}
+       }
+
+
+       /**
+        * Constructor
+        * @param inApp App object to pass results of drop back to
+        */
+       public FileDropHandler(App inApp)
+       {
+               _app = inApp;
+       }
+
+       /**
+        * Check if the object being dragged can be accepted
+        * @param inSupport object to check
+        */
+       public boolean canImport(TransferSupport inSupport)
+       {
+               boolean retval = inSupport.isDataFlavorSupported(DataFlavor.javaFileListFlavor)
+                       || inSupport.isDataFlavorSupported(_uriListFlavour);
+               // Modify icon to show a copy, not a move (+ icon on cursor)
+               if (retval) {
+                       inSupport.setDropAction(COPY);
+               }
+               return retval;
+       }
+
+       /**
+        * Accept the incoming data and pass it on to the App
+        * @param inSupport contents of drop
+        */
+       public boolean importData(TransferSupport inSupport)
+       {
+               if (!canImport(inSupport)) {return false;} // not allowed
+
+               boolean success = false;
+               ArrayList<File> dataFiles = new ArrayList<File>();
+
+               // Try a java file list flavour first
+               try
+               {
+                       @SuppressWarnings("unchecked")
+                       java.util.List<File> fileList = (java.util.List<File>)
+                       inSupport.getTransferable().getTransferData(DataFlavor.javaFileListFlavor);
+                       success = true;
+
+                       for (File f : fileList)
+                       {
+                               if (f != null && f.exists())
+                               {
+                                       if (f.isDirectory()) {
+                                               addDirectoryToList(f, dataFiles);
+                                       }
+                                       else if (f.isFile()) {
+                                               dataFiles.add(f);
+                                       }
+                               }
+                       }
+               } catch (Exception e) {}  // exception caught, probably missing a javafilelist flavour - just continue
+
+               // If that didn't work, try a list of strings instead
+               if (!success)
+               {
+                       try
+                       {
+                               String pathList = inSupport.getTransferable().getTransferData(_uriListFlavour).toString();
+                               success = true;
+
+                               for (String s : pathList.split("[\n\r]+"))
+                               {
+                                       if (s != null && !s.equals(""))
+                                       {
+                                               File f = new File(new URI(s));
+                                               if (f.exists())
+                                               {
+                                                       if (f.isDirectory()) {
+                                                               addDirectoryToList(f, dataFiles);
+                                                       }
+                                                       else if (f.isFile()) {
+                                                               dataFiles.add(f);
+                                                       }
+                                               }
+                                       }
+                               }
+                       } catch (Exception e) {
+                               System.err.println("exception: " + e.getClass().getName() + " - " + e.getMessage());
+                               return false;
+                       }
+               }
+
+               // Pass files back to app
+               if (!dataFiles.isEmpty()) {
+                       _app.loadDataFiles(dataFiles);
+               }
+               return true;
+       }
+
+
+       /**
+        * Recursively-called method to add files from the given directory (and its subdirectories)
+        * to the given list of files
+        * @param inDir directory to add
+        * @param inList file list to append to
+        */
+       private void addDirectoryToList(File inDir, ArrayList<File> inList)
+       {
+               if (inDir != null && inDir.exists() && inDir.canRead() && inDir.isDirectory() && inList != null)
+               {
+                       for (String path : inDir.list())
+                       {
+                               if (path != null)
+                               {
+                                       File f = new File(inDir, path);
+                                       if (f.exists() && f.canRead())
+                                       {
+                                               if (f.isFile())
+                                               {
+                                                       // Add the found file to the list (if it's not in there already)
+                                                       if (!inList.contains(f)) {
+                                                               inList.add(f);
+                                                       }
+                                               }
+                                               else if (f.isDirectory())
+                                               {
+                                                       // Recursively add the files from subdirectories
+                                                       addDirectoryToList(f, inList);
+                                               }
+                                       }
+                               }
+                       }
+               }
+       }
+}