ADD: Drag and drop - option to move instead copy (fixes #271)

(cherry picked from commit c42011485b)

src/fileviews/ufileviewwithmainctrl.pas

@@ -698,7 +698,8 @@ begin
     DropParams := TDropParams.Create(
       SourceFiles, // Will be freed automatically.
       GetDropEffectByKeyAndMouse(GetKeyShiftStateEx,
-                                 SourcePanel.FMainControlLastMouseButton),
+                                 SourcePanel.FMainControlLastMouseButton,
+                                 gDefaultDropEffect),
       MainControl.ClientToScreen(Classes.Point(X, Y)),
       True,
       SourcePanel, Self,
@@ -1400,7 +1401,7 @@ var
 begin
   if (DragManager <> nil) and DragManager.IsDragging then
     begin
-      DropEffect := GetDropEffectByKey(Shift);
+      DropEffect := GetDropEffectByKey(Shift, gDefaultDropEffect);
 
       if DropEffect = DropMoveEffect then
         TControlHandlersHack(MainControl).DragCursor:= crArrowMove

src/fmain.pas

@@ -1478,7 +1478,7 @@ begin
         TargetPath := IncludeTrailingPathDelimiter(TargetPath);
         if not Assigned(TargetFileSource) then
           TargetFileSource := TFileSystemFileSource.GetFileSource;
-        case GetDropEffectByKeyAndMouse(GetKeyShiftStateEx, mbLeft) of
+        case GetDropEffectByKeyAndMouse(GetKeyShiftStateEx, mbLeft, gDefaultDropEffect) of
           DropCopyEffect:
             Self.CopyFiles(ActiveFrame.FileSource, TargetFileSource, SourceFiles, TargetPath, gShowDialogOnDragDrop);
           DropMoveEffect:
@@ -1886,7 +1886,7 @@ begin
 
         DropParams := TDropParams.Create(
             Files,
-            GetDropEffectByKeyAndMouse(GetKeyShiftState, mbLeft),
+            GetDropEffectByKeyAndMouse(GetKeyShiftState, mbLeft, gDefaultDropEffect),
             Point, False,
             nil, TargetFileView,
             TargetFileView.FileSource,
@@ -2687,7 +2687,7 @@ begin
         begin
           TargetPath := ANotebook.View[ATabIndex].CurrentPath;
           TargetFileSource := ANotebook.View[ATabIndex].FileSource;
-          case GetDropEffectByKeyAndMouse(GetKeyShiftStateEx, mbLeft) of
+          case GetDropEffectByKeyAndMouse(GetKeyShiftStateEx, mbLeft, gDefaultDropEffect) of
             DropCopyEffect:
               Self.CopyFiles(ActiveFrame.FileSource, TargetFileSource, SourceFiles, TargetPath, gShowDialogOnDragDrop);
             DropMoveEffect:

src/platform/udragdropex.pas

@@ -163,8 +163,10 @@ type
   { Analyzes keyboard modifier keys (Shift, Ctrl, etc.) and mouse button nr
     and returns the appropriate drop effect. }
   function GetDropEffectByKeyAndMouse(ShiftState: TShiftState;
-                                      MouseButton: TMouseButton): TDropEffect;
-  function GetDropEffectByKey(ShiftState: TShiftState): TDropEffect;
+                                      MouseButton: TMouseButton;
+                                      DefaultEffect: Boolean): TDropEffect;
+  function GetDropEffectByKey(ShiftState: TShiftState;
+                              DefaultEffect: Boolean): TDropEffect;
 
 var
   { If set to True, then dragging is being transformed: internal to external or vice-versa. }
@@ -192,6 +194,8 @@ uses
   uDragDropQt;
 {$ENDIF}
 
+const
+  DropDefaultEffect: array[Boolean] of TDropEffect = (DropMoveEffect, DropCopyEffect);
 
 { ---------- TDragDropSource ---------- }
 
@@ -386,19 +390,20 @@ begin
 {$ENDIF}
 end;
 
-function GetDropEffectByKey(ShiftState: TShiftState): TDropEffect;
+function GetDropEffectByKey(ShiftState: TShiftState;
+                            DefaultEffect: Boolean): TDropEffect;
 const
   ssBoth = [ssLeft, ssRight];
 begin
   if (ssBoth * ShiftState = ssBoth) then
-    Exit(DropMoveEffect);
+    Exit(DropDefaultEffect[not DefaultEffect]);
   ShiftState := [ssModifier, ssShift, ssAlt] * ShiftState;
   if ShiftState = [] then
-    Result := DropCopyEffect   // default to Copy when no keys pressed
+    Result := DropDefaultEffect[DefaultEffect]   // default to Copy when no keys pressed
   else if ShiftState = [ssShift] then
-    Result := DropMoveEffect
+    Result := DropDefaultEffect[not DefaultEffect]
   else if ShiftState = [ssModifier] then
-    Result := DropMoveEffect
+    Result := DropDefaultEffect[not DefaultEffect]
   else if ShiftState = [ssAlt] then
     Result := DropAskEffect
   else if ShiftState = [ssModifier, ssShift] then
@@ -408,15 +413,16 @@ begin
 end;
 
 function GetDropEffectByKeyAndMouse(ShiftState: TShiftState;
-                                    MouseButton: TMouseButton): TDropEffect;
+                                    MouseButton: TMouseButton;
+                                    DefaultEffect: Boolean): TDropEffect;
 begin
   case MouseButton of
     mbLeft:
       begin
         if ShiftState = [ssRight] then
-          Result := DropMoveEffect
+          Result := DropDefaultEffect[not DefaultEffect]
         else
-          Result := GetDropEffectByKey(ShiftState);
+          Result := GetDropEffectByKey(ShiftState, DefaultEffect);
       end;
 
     mbMiddle:

src/uglobs.pas

@@ -482,6 +482,7 @@ var
   gShowCopyTabSelectPanel:boolean;
   gUseTrash : Boolean; // if using delete to trash by default
   gRenameSelOnlyName:boolean;
+  gDefaultDropEffect: Boolean;
   gShowDialogOnDragDrop: Boolean;
   gDragAndDropDesiredTextFormat:array[0..pred(NbOfDropTextFormat)] of tDesiredDropTextFormat;
   gDragAndDropAskFormatEachTime: Boolean;
@@ -1913,6 +1914,7 @@ begin
   gUseTrash := True;
   gSkipFileOpError := False;
   gTypeOfDuplicatedRename := drLegacyWithCopy;
+  gDefaultDropEffect:= True;
   gShowDialogOnDragDrop := True;
   gDragAndDropDesiredTextFormat[DropTextRichText_Index].Name:='Richtext format';
   gDragAndDropDesiredTextFormat[DropTextRichText_Index].DesireLevel:=0;
@@ -2874,6 +2876,7 @@ begin
       gUseTrash := GetValue(Node, 'UseTrash', gUseTrash);
       gSkipFileOpError := GetValue(Node, 'SkipFileOpError', gSkipFileOpError);
       gTypeOfDuplicatedRename := tDuplicatedRename(GetValue(Node, 'TypeOfDuplicatedRename', Integer(gTypeOfDuplicatedRename)));
+      gDefaultDropEffect := GetValue(Node, 'DefaultDropEffect', gDefaultDropEffect);
       gShowDialogOnDragDrop := GetValue(Node, 'ShowDialogOnDragDrop', gShowDialogOnDragDrop);
       gDragAndDropDesiredTextFormat[DropTextRichText_Index].DesireLevel := GetValue(Node, 'DragAndDropTextRichtextDesireLevel', gDragAndDropDesiredTextFormat[DropTextRichText_Index].DesireLevel);
       gDragAndDropDesiredTextFormat[DropTextHtml_Index].DesireLevel := GetValue(Node, 'DragAndDropTextHtmlDesireLevel',gDragAndDropDesiredTextFormat[DropTextHtml_Index].DesireLevel);
@@ -3543,6 +3546,7 @@ begin
     SetValue(Node, 'UseTrash', gUseTrash);
     SetValue(Node, 'SkipFileOpError', gSkipFileOpError);
     SetValue(Node, 'TypeOfDuplicatedRename', Integer(gTypeOfDuplicatedRename));
+    SetValue(Node, 'DefaultDropEffect', gDefaultDropEffect);
     SetValue(Node, 'ShowDialogOnDragDrop', gShowDialogOnDragDrop);
     SetValue(Node, 'DragAndDropTextRichtextDesireLevel', gDragAndDropDesiredTextFormat[DropTextRichText_Index].DesireLevel);
     SetValue(Node, 'DragAndDropTextHtmlDesireLevel',gDragAndDropDesiredTextFormat[DropTextHtml_Index].DesireLevel);