Added support to be able to control drag and drop positions in BoardView

Ernestchang · Aug 31, 2017 · cb2bc9a · cb2bc9a
1 parent 2910baa
commit cb2bc9a
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Showing 7 changed files with 93 additions and 33 deletions.
diff --git a/README.md b/README.md
@@ -19,7 +19,7 @@ Youtube demo video<br>
     }
 
     dependencies {
-        compile 'com.github.woxthebox:draglistview:1.4.7'
+        compile 'com.github.woxthebox:draglistview:1.4.8'
     }
 
 Add this to proguard rules, otherwise animations won't work correctly
@@ -158,25 +158,38 @@ List and Grid layouts are used as example in the sample project.
         mBoardView.setSnapToColumnInLandscape(false);
         mBoardView.setColumnSnapPosition(BoardView.ColumnSnapPosition.CENTER);
         mBoardView.setBoardListener(new BoardView.BoardListener() {
-              @Override
-              public void onItemDragStarted(int column, int row) {
-                  Toast.makeText(getActivity(), "Start - column: " + column + " row: " + row, Toast.LENGTH_SHORT).show();
-              }
-
-              @Override
-              public void onItemChangedColumn(int oldColumn, int newColumn) {
-                  TextView itemCount1 = (TextView) mBoardView.getHeaderView(oldColumn).findViewById(R.id.item_count);
-                  itemCount1.setText("" + mBoardView.getAdapter(oldColumn).getItemCount());
-                  TextView itemCount2 = (TextView) mBoardView.getHeaderView(newColumn).findViewById(R.id.item_count);
-                  itemCount2.setText("" + mBoardView.getAdapter(newColumn).getItemCount());
-              }
-
-              @Override
-              public void onItemDragEnded(int fromColumn, int fromRow, int toColumn, int toRow) {
-                  if (fromColumn != toColumn || fromRow != toRow) {
-                      Toast.makeText(getActivity(), "End - column: " + toColumn + " row: " + toRow, Toast.LENGTH_SHORT).show();
-                  }
-              }
+            @Override
+            public void onItemDragStarted(int column, int row) {
+                Toast.makeText(getActivity(), "Start - column: " + column + " row: " + row, Toast.LENGTH_SHORT).show();
+            }
+
+            @Override
+            public void onItemChangedColumn(int oldColumn, int newColumn) {
+                TextView itemCount1 = (TextView) mBoardView.getHeaderView(oldColumn).findViewById(R.id.item_count);
+                itemCount1.setText("" + mBoardView.getAdapter(oldColumn).getItemCount());
+                TextView itemCount2 = (TextView) mBoardView.getHeaderView(newColumn).findViewById(R.id.item_count);
+                itemCount2.setText("" + mBoardView.getAdapter(newColumn).getItemCount());
+            }
+
+            @Override
+            public void onItemDragEnded(int fromColumn, int fromRow, int toColumn, int toRow) {
+                if (fromColumn != toColumn || fromRow != toRow) {
+                  Toast.makeText(getActivity(), "End - column: " + toColumn + " row: " + toRow, Toast.LENGTH_SHORT).show();
+                }
+            }
+        });
+        mBoardView.setBoardCallback(new BoardView.BoardCallback() {
+            @Override
+            public boolean canDragItemAtPosition(int column, int dragPosition) {
+                // Add logic here to prevent an item to be dragged
+                return true;
+            }
+
+            @Override
+            public boolean canDropItemAtPosition(int oldColumn, int oldRow, int newColumn, int newRow) {
+                // Add logic here to prevent an item to be dropped
+                return true;
+            }
         });
         ...
         mBoardView.addColumnList(listAdapter, header, false);

diff --git a/library/build.gradle b/library/build.gradle
@@ -2,7 +2,7 @@ apply plugin: 'com.android.library'
 
 android {
     compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    buildToolsVersion "25.0.3"
 
     defaultConfig {
         minSdkVersion 11

diff --git a/library/gradle.properties b/library/gradle.properties
@@ -1,5 +1,5 @@
-VERSION_NAME=1.4.7
-VERSION_CODE=38
+VERSION_NAME=1.4.8
+VERSION_CODE=39
 GROUP=com.github.woxthebox
 
 POM_DESCRIPTION=Drag and drop to re-order items in a list, grid or board.

diff --git a/library/src/main/java/com/woxthebox/draglistview/BoardView.java b/library/src/main/java/com/woxthebox/draglistview/BoardView.java
@@ -53,6 +53,12 @@ public interface BoardListener {
         void onItemDragEnded(int fromColumn, int fromRow, int toColumn, int toRow);
     }
 
+    public interface BoardCallback {
+        boolean canDragItemAtPosition(int column, int row);
+
+        boolean canDropItemAtPosition(int oldColumn, int oldRow, int newColumn, int newRow);
+    }
+
     public enum ColumnSnapPosition {
         LEFT, CENTER, RIGHT
     }
@@ -68,6 +74,7 @@ public enum ColumnSnapPosition {
     private DragItemRecyclerView mCurrentRecyclerView;
     private DragItem mDragItem;
     private BoardListener mBoardListener;
+    private BoardCallback mBoardCallback;
     private boolean mSnapToColumnWhenScrolling = true;
     private boolean mSnapToColumnWhenDragging = true;
     private boolean mSnapToColumnInLandscape = false;
@@ -265,14 +272,19 @@ private void updateScrollPosition() {
             int oldColumn = getColumnOfList(mCurrentRecyclerView);
             int newColumn = getColumnOfList(currentList);
             long itemId = mCurrentRecyclerView.getDragItemId();
-            Object item = mCurrentRecyclerView.removeDragItemAndEnd();
-            if (item != null) {
-                mCurrentRecyclerView = currentList;
-                mCurrentRecyclerView.addDragItemAndStart(getListTouchY(mCurrentRecyclerView), item, itemId);
-                mDragItem.setOffset(((View) mCurrentRecyclerView.getParent()).getLeft(), mCurrentRecyclerView.getTop());
 
-                if (mBoardListener != null) {
-                    mBoardListener.onItemChangedColumn(oldColumn, newColumn);
+            // Check if it is ok to drop the item in the new column first
+            int newPosition = currentList.getDragPositionForY(getListTouchY(currentList));
+            if (mBoardListener == null || mBoardCallback.canDropItemAtPosition(mDragStartColumn, mDragStartRow, newColumn, newPosition)) {
+                Object item = mCurrentRecyclerView.removeDragItemAndEnd();
+                if (item != null) {
+                    mCurrentRecyclerView = currentList;
+                    mCurrentRecyclerView.addDragItemAndStart(getListTouchY(mCurrentRecyclerView), item, itemId);
+                    mDragItem.setOffset(((View) mCurrentRecyclerView.getParent()).getLeft(), mCurrentRecyclerView.getTop());
+
+                    if (mBoardListener != null) {
+                        mBoardListener.onItemChangedColumn(oldColumn, newColumn);
+                    }
                 }
             }
         }
@@ -594,6 +606,10 @@ public void setBoardListener(BoardListener listener) {
         mBoardListener = listener;
     }
 
+    public void setBoardCallback(BoardCallback callback) {
+        mBoardCallback = callback;
+    }
+
     public void setCustomDragItem(DragItem dragItem) {
         DragItem newDragItem;
         if (dragItem != null) {
@@ -651,6 +667,19 @@ public void onDragEnded(int newItemPosition) {
                 }
             }
         });
+        recyclerView.setDragItemCallback(new DragItemRecyclerView.DragItemCallback() {
+            @Override
+            public boolean canDragItemAtPosition(int dragPosition) {
+                int column = getColumnOfList(recyclerView);
+                return mBoardCallback == null || mBoardCallback.canDragItemAtPosition(column, dragPosition);
+            }
+
+            @Override
+            public boolean canDropItemAtPosition(int dropPosition) {
+                int column = getColumnOfList(recyclerView);
+                return mBoardCallback == null || mBoardCallback.canDropItemAtPosition(mDragStartColumn, mDragStartRow, column, dropPosition);
+            }
+        });
 
         recyclerView.setAdapter(adapter);
         recyclerView.setDragEnabled(mDragEnabled);

diff --git a/library/src/main/java/com/woxthebox/draglistview/DragItemRecyclerView.java b/library/src/main/java/com/woxthebox/draglistview/DragItemRecyclerView.java
@@ -460,7 +460,7 @@ private void onDragItemAnimationEnd() {
         invalidate();
     }
 
-    void addDragItemAndStart(float y, Object item, long itemId) {
+    int getDragPositionForY(float y) {
         View child = findChildView(0, y);
         int pos;
         if (child == null && getChildCount() > 0) {
@@ -476,6 +476,11 @@ void addDragItemAndStart(float y, Object item, long itemId) {
         if (pos == NO_POSITION) {
             pos = 0;
         }
+        return pos;
+    }
+
+    void addDragItemAndStart(float y, Object item, long itemId) {
+        int pos = getDragPositionForY(y);
 
         mDragState = DragState.DRAG_STARTED;
         mDragItemId = itemId;

diff --git a/sample/build.gradle b/sample/build.gradle
@@ -2,7 +2,7 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    buildToolsVersion "25.0.3"
 
     defaultConfig {
         applicationId "com.woxthebox.draglistview.sample"

diff --git a/sample/src/main/java/com/woxthebox/draglistview/sample/BoardFragment.java b/sample/src/main/java/com/woxthebox/draglistview/sample/BoardFragment.java
@@ -75,7 +75,7 @@ public void onItemDragStarted(int column, int row) {
 
             @Override
             public void onItemChangedPosition(int oldColumn, int oldRow, int newColumn, int newRow) {
-                Toast.makeText(mBoardView.getContext(), "Position changed - column: " + newColumn + " row: " + newRow, Toast.LENGTH_SHORT).show();
+                //Toast.makeText(mBoardView.getContext(), "Position changed - column: " + newColumn + " row: " + newRow, Toast.LENGTH_SHORT).show();
             }
 
             @Override
@@ -93,6 +93,19 @@ public void onItemDragEnded(int fromColumn, int fromRow, int toColumn, int toRow
                 }
             }
         });
+        mBoardView.setBoardCallback(new BoardView.BoardCallback() {
+            @Override
+            public boolean canDragItemAtPosition(int column, int dragPosition) {
+                // Add logic here to prevent an item to be dragged
+                return true;
+            }
+
+            @Override
+            public boolean canDropItemAtPosition(int oldColumn, int oldRow, int newColumn, int newRow) {
+                // Add logic here to prevent an item to be dropped
+                return true;
+            }
+        });
         return view;
     }