IDE: in the Treeview Items Editor, add the ability to save a treeview as xml. Part of issue #40806.

components/ideintf/treeviewpropedit.lfm

@@ -12,7 +12,7 @@ object TreeViewItemsEditorForm: TTreeViewItemsEditorForm
   Constraints.MinWidth = 400
   KeyPreview = True
   Position = poScreenCenter
-  LCLVersion = '3.99.0.0'
+  LCLVersion = '4.99.0.0'
   OnActivate = FormActivate
   OnClose = FormClose
   OnCreate = FormCreate
@@ -39,7 +39,7 @@ object TreeViewItemsEditorForm: TTreeViewItemsEditorForm
     ShowBevel = False
     object btnApply: TBitBtn
       AnchorSideBottom.Side = asrBottom
-      Left = 357
+      Left = 379
       Height = 26
       Hint = '[Shift+Enter]'
       Top = 0

components/ideintf/treeviewpropedit.pas

@@ -21,7 +21,9 @@ uses
   Classes, SysUtils,
   // LCL
   LCLType, Forms, Dialogs, Buttons, Controls, StdCtrls, ComCtrls, ImgList, Spin,
-  ButtonPanel, ExtCtrls,
+  ButtonPanel, ExtCtrls, TreeStorage,
+  //LazUtils,
+  FileUtil, LazFileUtils,
   // IdeIntf
   PropEdits, ComponentEditors, ObjInspStrConsts, IDEImagesIntf, IDEWindowIntf;
 
@@ -154,6 +156,7 @@ begin
   // dialogs
   dlgOpen.Title := sccsTrEdtOpenDialog;
   dlgSave.Title := sccsTrEdtSaveDialog;
+  dlgSave.Filter := 'xml files|*.xml|All files|'+GetAllFilesMask+'|';
 
   // button panel
   ButtonPanel.ShowHint := true;
@@ -433,6 +436,8 @@ begin
 end;
 
 procedure TTreeViewItemsEditorForm.tbSaveClick(Sender: TObject);
+var
+  Fn: String;
 
   function ImagesFound: boolean;
   var
@@ -469,9 +474,21 @@ procedure TTreeViewItemsEditorForm.tbSaveClick(Sender: TObject);
 
 begin
   FinishNodeEditing;
-
-  if ConfirmImagesLoss and dlgSave.Execute and ConfirmFileReplace then
-    treEditor.SaveToFile(dlgSave.FileName);
+  if dlgSave.Execute and ConfirmFileReplace then
+  begin
+    Fn := dlgSave.FileName;
+    if (CompareFileExt(Fn, 'xml', False) = 0) then
+    begin
+      TreeSaveToXML(treEditor, Fn);
+    end
+    else
+    begin
+      if ConfirmImagesLoss then
+        treEditor.SaveToFile(Fn);
+    end;
+  end;
+  //if ConfirmImagesLoss and dlgSave.Execute and ConfirmFileReplace then
+  //  treEditor.SaveToFile(dlgSave.FileName);
 end;
 
 procedure TTreeViewItemsEditorForm.spnIndexChange(Sender: TObject);