Prevent folders from drag and dropping onto themselves in dolphin main view

Summary:
This patch aims to improve user experience by not allowing the user to drag and drop a folder into itself.

The current behavior shows a red message at the top which can then be closed by the user, instead of relying on that, this patch disables the option of dropping onto self and uses the "Invalid drop target cursor" to highlight the behavior.

BUG: 307747

Since spectacle is unable to screenshot the cursor overlay, find attached a photo of the screen.
{F3787651}

Test Plan:
1. Drag a folder.
2. Drop it onto itself.

Reviewers: #dolphin, elvisangelaccio, ngraham, rkflx, dfaure

Reviewed By: #dolphin, elvisangelaccio, rkflx, dfaure

Subscribers: rkflx, ngraham, elvisangelaccio, dfaure, anthonyfieroni, #konqueror

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D6281

2 files changed, 7 insertions, 0 deletions

diff --git a/src/panels/places/placesitemmodel.cpp b/src/panels/places/placesitemmodel.cpp
index abd6bc925..680d513b5 100644
--- a/src/panels/places/placesitemmodel.cpp
+++ b/src/panels/places/placesitemmodel.cpp
@@ -1159,6 +1159,12 @@ QString PlacesItemModel::timelineDateString(int year, int month, int day)
     return date;
 }
 
+bool PlacesItemModel::isDir(int index) const
+{
+    Q_UNUSED(index);
+    return true;
+}
+
 QUrl PlacesItemModel::createSearchUrl(const QUrl& url)
 {
     QUrl searchUrl;
diff --git a/src/panels/places/placesitemmodel.h b/src/panels/places/placesitemmodel.h
index dcc9759e6..7dd49bf5a 100644
--- a/src/panels/places/placesitemmodel.h
+++ b/src/panels/places/placesitemmodel.h
@@ -132,6 +132,7 @@ public:
      */
     void saveBookmarks();
 
+    bool isDir(int index) const Q_DECL_OVERRIDE;
 signals:
     void errorMessage(const QString& message);
     void storageSetupDone(int index, bool success);