Beginning work on the directory traversals (partially working)

Author: maxieds

AndroidFilePickerLightLibrary/src/main/java/com/maxieds/androidfilepickerlightlibrary/BasicFileProvider.java

@@ -188,6 +188,18 @@ public boolean enterNextSubfolder(String subfolderPath) {
         return status;
     }
 
+    public boolean backOneFolder() {
+        if(baseDirPath == null) {
+            return false;
+        }
+        File parentFolder = baseDirPath.getParentFile();
+        if(parentFolder != null) {
+            baseDirPath = parentFolder;
+            return true;
+        }
+        return false;
+    }
+
     @Override
     public boolean onCreate() {
         if(fileProviderStaticInst == null) {

AndroidFilePickerLightLibrary/src/main/java/com/maxieds/androidfilepickerlightlibrary/DisplayFragments.java

@@ -178,20 +178,21 @@ public void descendIntoNextDirectory(boolean initNewFileTree) {
 
             // Completely clear out the previously displayed contents:
             FileChooserRecyclerView mainRV = getMainRecyclerView();
+            mainRV.invalidate();
             DisplayAdapters.FileListAdapter rvAdapter = (DisplayAdapters.FileListAdapter) mainRV.getAdapter();
             int priorAdapterCount = rvAdapter.getItemCount();
             rvAdapter.reloadDataSets(new ArrayList<String>(), new ArrayList<DisplayTypes.FileType>(), false);
             rvAdapter.notifyItemRangeRemoved(0, priorAdapterCount);
             rvAdapter.notifyDataSetChanged();
             mainRV.removeAllViews();
             mainRV.removeAllViewsInLayout();
-            mainRV.invalidate();
+
+            // ??? TODO: Later, may want to display a loading notice if initializing a new directory is sluggish ???
 
             // Descend into the next directory:
             lastFileDataStartIndex = 0;
-            lastFileDataEndIndex = lastFileDataStartIndex + getViewportMaxFilesCount() - 1;
+            lastFileDataEndIndex = Math.min(Math.max(0, nextFolder.getFolderChildCount() - 1), lastFileDataStartIndex + getViewportMaxFilesCount() - 1);
             setCwdFolderContext(nextFolder);
-            // ??? TODO: Later, may want to display a loading notice if initializing a new directory is sluggish ???
             getCwdFolderContext().computeDirectoryContents(lastFileDataStartIndex, lastFileDataEndIndex);
             displayNextDirectoryFilesList(getCwdFolderContext().getWorkingDirectoryContents());
             DisplayFragments.FolderNavigationFragment.dirsOneBackText.setText(folderHistoryOneBackPath);
@@ -299,32 +300,14 @@ public static void resetLayout(View layoutContainer, DisplayTypes.FileType fileI
 
     public static class FolderNavigationFragment {
 
-        private static FolderNavigationFragment folderNavFragmentStaticInst = null;
         public static TextView dirsTwoBackText = null;
         public static TextView dirsOneBackText = null;
-        public static ImageButton globalNavBackBtn = null;
-
-        public FolderNavigationFragment() {
-            folderNavFragmentStaticInst = this;
-        }
 
         public static FolderNavigationFragment createNewFolderNavFragment(View navBtnsContainerView) {
             FolderNavigationFragment folderNavFragment = new FolderNavigationFragment();
             dirsTwoBackText = FileChooserActivity.getInstance().findViewById(R.id.mainDirNavBackTwoPathDisplayText);
             dirsOneBackText = FileChooserActivity.getInstance().findViewById(R.id.mainDirNavBackOnePathDisplayText);
-            globalNavBackBtn = FileChooserActivity.getInstance().findViewById(R.id.mainDirNavGlobalBackBtn);
             updateFolderHistoryPaths(null, true);
-            Button.OnClickListener backBtnClickListener = new Button.OnClickListener() {
-                @Override
-                public void onClick(View btnView) {
-                     ImageButton navBtn = (ImageButton) btnView;
-                     String baseFolderTypeName = btnView.getTag().toString();
-                     FileChooserBuilder.BaseFolderPathType baseFolderPathType = FileChooserBuilder.BaseFolderPathType.getInstanceByName(baseFolderTypeName);
-                     BasicFileProvider.getInstance().selectBaseDirectoryByType(baseFolderPathType);
-                     getInstance().initiateNewFolderLoad(baseFolderPathType);
-                }
-            };
-            globalNavBackBtn.setOnClickListener(backBtnClickListener);
             return folderNavFragment;
         }
     }

AndroidFilePickerLightLibrary/src/main/java/com/maxieds/androidfilepickerlightlibrary/DisplayTypes.java

@@ -235,6 +235,26 @@ public static DirectoryResultContext probeAtCursoryFolderQuery(String nextSubfol
             return probeAtCursoryFolderQueryGetNext();
         }
 
+        public static DirectoryResultContext probePreviousFolder(int howManyBackwards) {
+            BasicFileProvider fpInst = BasicFileProvider.getInstance();
+            if(fpInst == null) {
+                return null;
+            }
+            else {
+                fpInst.setCustomFileFilter(DisplayFragments.getInstance().localFilesListFilter);
+                fpInst.setCustomFolderSort(DisplayFragments.getInstance().localFilesListSortFunc);
+            }
+            if(howManyBackwards <= 0) {
+                return null;
+            }
+            while(--howManyBackwards >= 0) {
+                if(!fpInst.backOneFolder()) {
+                    return null;
+                }
+            }
+            return probeAtCursoryFolderQueryGetNext();
+        }
+
     }
 
     public static class FileType {

AndroidFilePickerLightLibrary/src/main/java/com/maxieds/androidfilepickerlightlibrary/FileChooserActivity.java

@@ -184,6 +184,29 @@ public void onClick(View btnView) {
             fileDirsNavButtonsContainer.addView(dirNavBtn);
         }
 
+        /*
+         * Handle setting up the default graphical back button:
+         * It should take the user (loading in the correct directory context) backwards on
+         * folder into which they have traversed. If no folders have been entered, it returns
+         * an empty selection back to the client application.
+         */
+        ImageButton backBtn = findViewById(R.id.mainDirNavGlobalBackBtn);
+        backBtn.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                DisplayFragments displayCtx = DisplayFragments.getInstance();
+                if(displayCtx.pathHistoryStack.empty()) {
+                    getInstance().postSelectedFilesActivityResult(new FileChooserException.CommunicateNoDataException());
+                }
+                String displayAscendingPrecurseMsg = String.format(Locale.getDefault(), "Ascending back upwards into DIR \"%s\".",
+                        displayCtx.pathHistoryStack.peek().getCWDBasePath());
+                DisplayUtils.displayToastMessageShort(displayAscendingPrecurseMsg);
+                displayCtx.descendIntoNextDirectory(false);
+            }
+        });
+        LinearLayout dirHistoryNavContainer = (LinearLayout) findViewById(R.id.mainDirPrevPathsNavContainer);
+        DisplayFragments.mainFolderNavFragment = DisplayFragments.FolderNavigationFragment.createNewFolderNavFragment(dirHistoryNavContainer);
+
         /* The next level of navigation in a top down order is the action buttons to finish or cancel
          * the user's file selection procedure. These need onClick handlers that are mostly separate
          * and less involved that the corresponding RecyclerView and files listing UI actions.
@@ -215,16 +238,6 @@ public void onClick(View btnView) {
         };
         doneActionBtn.setOnClickListener(doneActivityBtnClickListener);
 
-        /*
-         * Last, there is the global back button and previous directory history display.
-         * Note that unless a completely different path trajectory is selected by the user
-         * (with the last level of directory select nav buttons), we keep a working
-         * stack of the last paths for context. If the back button is pressed and the stack is
-         * empty, this action is handled the same way as a cancel button press by the user.
-         */
-        LinearLayout dirHistoryNavContainer = (LinearLayout) findViewById(R.id.mainDirPrevPathsNavContainer);
-        DisplayFragments.mainFolderNavFragment = DisplayFragments.FolderNavigationFragment.createNewFolderNavFragment(dirHistoryNavContainer);
-
         /* Setup some theme related styling on the main file list container: */
         FileChooserRecyclerView mainLayoutRecyclerView = findViewById(R.id.mainRecyclerView);
         getDisplayFragmentsInstance().initializeRecyclerViewLayout(mainLayoutRecyclerView);

AndroidFilePickerLightLibrary/src/main/java/com/maxieds/androidfilepickerlightlibrary/FileChooserBuilder.java

@@ -405,10 +405,10 @@ public void launchFilePicker() throws FileChooserException.AndroidFilePickerLigh
         activityContextRef.get().startActivityForResult(launchPickerIntent, activityActionCode);
     }
 
-    public static final int ACTIVITY_CODE_SELECT_FILE = 1;
-    public static final int ACTIVITY_CODE_SELECT_DIRECTORY_ONLY = 2;
-    public static final int ACTIVITY_CODE_SELECT_MULTIPLE_FILES = 3;
-    public static final int ACTIVITY_CODE_BRING_TO_FRONT = 4;
+    private static final int FILE_PICKER_SWIZZLED_BITS_OFFSET = (8080 << 3) + 2;
+    public static final int ACTIVITY_CODE_SELECT_FILE = 1 + FILE_PICKER_SWIZZLED_BITS_OFFSET;
+    public static final int ACTIVITY_CODE_SELECT_DIRECTORY_ONLY = 2 + FILE_PICKER_SWIZZLED_BITS_OFFSET;
+    public static final int ACTIVITY_CODE_SELECT_MULTIPLE_FILES = 3 + FILE_PICKER_SWIZZLED_BITS_OFFSET;
 
     /* Client code should call this method in their main Activity's onActivityResult function
      * to handle the logic there when the activity was created as a file picker instance: