From 55b51f1788e49766c1d23bf7a2f69db1d1b9de13 Mon Sep 17 00:00:00 2001
From: juha <juha@lazarus-ide.org>
Date: Sat, 18 Feb 2017 11:26:43 +0000
Subject: [PATCH] LCL: Implement TTreeView.MultiSelectStyle. Issue #18043,
 patch from AlexeyT.

git-svn-id: trunk@54187 -
---
 lcl/comctrls.pp          |  2 ++
 lcl/include/treeview.inc | 36 +++++++++++++++++++++++-------------
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/lcl/comctrls.pp b/lcl/comctrls.pp
index 7696787ba9..f1b45f8d22 100644
--- a/lcl/comctrls.pp
+++ b/lcl/comctrls.pp
@@ -3383,6 +3383,8 @@ type
     procedure UpdateScrollbars;
     procedure UpdateTooltip(X, Y: integer);
     procedure InternalSelectionChanged;
+    function AllowMultiSelectWithCtrl(AState: TShiftState): Boolean;
+    function AllowMultiSelectWithShift(AState: TShiftState): Boolean;
   protected
     FChangeTimer: TTimer;
     FEditor: TEdit;
diff --git a/lcl/include/treeview.inc b/lcl/include/treeview.inc
index e6450a822a..cbe3b83645 100644
--- a/lcl/include/treeview.inc
+++ b/lcl/include/treeview.inc
@@ -4041,37 +4041,37 @@ begin
 
   VK_DOWN:
   begin
-    MoveToNextNode(ssShift in Shift);
+    MoveToNextNode(AllowMultiSelectWithShift(Shift));
     Key:=VK_UNKNOWN;
   end;
 
   VK_UP:
   begin
-    MoveToPrevNode(ssShift in Shift);
+    MoveToPrevNode(AllowMultiSelectWithShift(Shift));
     Key:=VK_UNKNOWN;
   end;
 
   VK_HOME:
   begin
-    MoveHome(ssShift in Shift);
+    MoveHome(AllowMultiSelectWithShift(Shift));
     Key:=VK_UNKNOWN;
   end;
 
   VK_END:
   begin
-    MoveEnd(ssShift in Shift);
+    MoveEnd(AllowMultiSelectWithShift(Shift));
     Key:=VK_UNKNOWN;
   end;
 
   VK_PRIOR: // Page Up
   begin
-    MovePageUp(ssShift in Shift);
+    MovePageUp(AllowMultiSelectWithShift(Shift));
     Key:=VK_UNKNOWN;
   end;
 
   VK_NEXT: // Page Down
   begin
-    MovePageDown(ssShift in Shift);
+    MovePageDown(AllowMultiSelectWithShift(Shift));
     Key:=VK_UNKNOWN;
   end;
 
@@ -4079,7 +4079,7 @@ begin
     if not (Key in [VK_LEFT,VK_RIGHT,VK_ADD,VK_SUBTRACT]) then
       Exit;
 
-    if (tvoAllowMultiSelect in FOptions) and (ssShift in Shift) then
+    if (tvoAllowMultiSelect in FOptions) and AllowMultiSelectWithShift(Shift) then
       lNode := FTreeNodes.FLastMultiSelected
     else
       lNode := Selected;
@@ -4121,7 +4121,7 @@ begin
     end;
 
     if lNode <> nil then
-      MoveSelection(lNode, ([ssShift] * Shift) <> []);
+      MoveSelection(lNode, AllowMultiSelectWithShift(Shift));
   end;
 end;
 
@@ -5361,7 +5361,7 @@ begin
   //change selection on right click
   if (Button = mbRight) and RightClickSelect and//right click
      (([ssDouble, ssTriple, ssQuad] * Shift) = []) and//single or first of a multi click
-     not(ssCtrl in Shift) and//only when CTRL is not pressed
+     not AllowMultiSelectWithCtrl(Shift) and//only when CTRL is not pressed
      (CursorNode <> nil) and
      (LogicalX >= CursorNode.DisplayStateIconLeft)//only after expand sign
   then
@@ -5409,17 +5409,17 @@ begin
         Selected := CursorNode
       else
       begin
-        if (ssShift in Shift) then
+        if AllowMultiSelectWithShift(Shift) then
         begin
           Exclude(FStates,tvsEditOnMouseUp);
           LockSelectionChangeEvent;
           try
-            Items.MultiSelect(CursorNode, not(ssCtrl in Shift));
+            Items.MultiSelect(CursorNode, not AllowMultiSelectWithCtrl(Shift));
           finally
             UnlockSelectionChangeEvent;
           end;
         end
-        else if (ssCtrl in Shift) then
+        else if AllowMultiSelectWithCtrl(Shift) then
         begin
           Exclude(FStates,tvsEditOnMouseUp);
           CursorNode.MultiSelected:=not CursorNode.MultiSelected;
@@ -5820,6 +5820,16 @@ begin
   end;
 end;
 
+function TCustomTreeView.AllowMultiSelectWithCtrl(AState: TShiftState): Boolean;
+begin
+  Result := (ssCtrl in AState) and (msControlSelect in FMultiSelectStyle);
+end;
+
+function TCustomTreeView.AllowMultiSelectWithShift(AState: TShiftState): Boolean;
+begin
+  Result := (ssShift in AState) and (msShiftSelect in FMultiSelectStyle);
+end;
+
 class procedure TCustomTreeView.WSRegisterClass;
 begin
   inherited WSRegisterClass;
@@ -6022,7 +6032,7 @@ end;
 
 procedure TCustomTreeView.Select(Node: TTreeNode; ShiftState: TShiftState = []);
 begin
-  if (tvoAllowMultiSelect in FOptions) and (ssCtrl in ShiftState) then
+  if (tvoAllowMultiSelect in FOptions) and AllowMultiSelectWithCtrl(ShiftState) then
     Node.Selected := True
   else begin
     ClearSelection;