From 5576446ed2a8b1a61a4310d6668bcc419ff35659 Mon Sep 17 00:00:00 2001
From: dmitry <dmitry@lazarus-ide.org>
Date: Fri, 14 Sep 2018 19:23:54 +0000
Subject: [PATCH] cocoa: common approach for handling TAB key and preventing
 Cocoa to switch the focus

git-svn-id: trunk@58995 -
---
 lcl/interfaces/cocoa/cocoaprivate.pas    |  1 +
 lcl/interfaces/cocoa/cocoatextedits.pas  | 10 ----------
 lcl/interfaces/cocoa/cocoawscommon.pas   | 17 +++++++++++++++--
 lcl/interfaces/cocoa/cocoawsstdctrls.pas |  4 ++--
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/lcl/interfaces/cocoa/cocoaprivate.pas b/lcl/interfaces/cocoa/cocoaprivate.pas
index 8149534247..76909b28c6 100644
--- a/lcl/interfaces/cocoa/cocoaprivate.pas
+++ b/lcl/interfaces/cocoa/cocoaprivate.pas
@@ -69,6 +69,7 @@ type
     procedure KeyEvPrepare(Event: NSEvent; AForceAsKeyDown: Boolean = False);
     procedure KeyEvBefore(out AllowCocoaHandle: boolean);
     procedure KeyEvAfter;
+    procedure SetTabSuppress(ASuppress: Boolean);
 
     function scrollWheel(Event: NSEvent): Boolean;
     // size, pos events
diff --git a/lcl/interfaces/cocoa/cocoatextedits.pas b/lcl/interfaces/cocoa/cocoatextedits.pas
index a8cc8f203a..489f6945af 100644
--- a/lcl/interfaces/cocoa/cocoatextedits.pas
+++ b/lcl/interfaces/cocoa/cocoatextedits.pas
@@ -114,7 +114,6 @@ type
     callback: ICommonCallback;
     FEnabled: Boolean;
 
-    allowTabs : Boolean;
     supressTextChangeEvent: Integer; // if above zero, then don't send text change event
 
     function acceptsFirstResponder: Boolean; override;
@@ -538,12 +537,7 @@ begin
   end;
 
   cb.KeyEvPrepare(event);
-  res := true;
   cb.KeyEvBefore(res);
-
-  //todo: this exceptional code for Tab should NOT be needed!
-  //      callback should take care all of that
-  res := res and (event.keyCode <> NSKeyCodeTab);
   if res then inherited keyDown(event);
   cb.KeyEvAfter;
 end;
@@ -810,10 +804,6 @@ begin
   begin
     callback.KeyEvPrepare(event);
     callback.KeyEvBefore(res);
-    res := res and (
-       // memo can get "tab" if it's allowed
-       ((event.keyCode <> NSKeyCodeTab) or (allowTabs))
-      );
     if res then inherited keyDown(event);
     callback.KeyEvAfter;
   end else
diff --git a/lcl/interfaces/cocoa/cocoawscommon.pas b/lcl/interfaces/cocoa/cocoawscommon.pas
index c5c1c53387..4caaedb468 100644
--- a/lcl/interfaces/cocoa/cocoawscommon.pas
+++ b/lcl/interfaces/cocoa/cocoawscommon.pas
@@ -52,6 +52,7 @@ type
     Owner: NSObject;
     Frame: NSObject;
     BlockCocoaUpDown: Boolean;
+    SuppressTabDown: Boolean; // all tabs should be suppressed, so Cocoa would not switch focus
 
     class constructor Create;
     constructor Create(AOwner: NSObject; ATarget: TWinControl); virtual;
@@ -71,6 +72,7 @@ type
     procedure KeyEvPrepare(Event: NSEvent; AForceAsKeyDown: Boolean = False);
     procedure KeyEvBefore(out AllowCocoaHandle: boolean);
     procedure KeyEvAfter;
+    procedure SetTabSuppress(ASuppress: Boolean);
 
     procedure MouseClick; virtual;
     function MouseMove(Event: NSEvent): Boolean; virtual;
@@ -301,6 +303,8 @@ begin
   FBoundsReportedToChildren:=false;
   FIsOpaque:=false;
   FIsEventRouting:=false;
+  SuppressTabDown := true; // by default all Tabs would not be allowed for Cocoa.
+                           // it should be enabled, i.e. for TMemo with WantTabs=true
 end;
 
 destructor TLCLCommonCallback.Destroy;
@@ -1102,8 +1106,12 @@ end;
 procedure TLCLCommonCallback.KeyEvBefore(out AllowCocoaHandle: boolean);
 begin
   AllowCocoaHandle := true;
-  if _IsKeyDown then KeyEvBeforeDown(AllowCocoaHandle)
-  else KeyEvBeforeUp(AllowCocoaHandle);
+  if _IsKeyDown then begin
+    KeyEvBeforeDown(AllowCocoaHandle);
+    if AllowCocoaHandle and SuppressTabDown and (_KeyMsg.CharCode = VK_TAB) then
+      AllowCocoaHandle := false;
+  end else
+    KeyEvBeforeUp(AllowCocoaHandle);
 end;
 
 procedure TLCLCommonCallback.KeyEvAfter;
@@ -1112,6 +1120,11 @@ begin
   else KeyEvAfterUp;
 end;
 
+procedure TLCLCommonCallback.SetTabSuppress(ASuppress: Boolean);
+begin
+  SuppressTabDown := ASuppress;
+end;
+
 procedure TLCLCommonCallback.MouseClick;
 begin
   LCLSendClickedMsg(Target);
diff --git a/lcl/interfaces/cocoa/cocoawsstdctrls.pas b/lcl/interfaces/cocoa/cocoawsstdctrls.pas
index e2bf8c9cd2..ea9425968f 100644
--- a/lcl/interfaces/cocoa/cocoawsstdctrls.pas
+++ b/lcl/interfaces/cocoa/cocoawsstdctrls.pas
@@ -1294,7 +1294,7 @@ begin
 
   TextViewSetWordWrap(txt, scr, TCustomMemo(AWinControl).WordWrap);
   TextViewSetAllignment(txt, TCustomMemo(AWinControl).Alignment);
-  txt.allowTabs := TCustomMemo(AWinControl).WantTabs;
+  txt.callback.SetTabSuppress(not TCustomMemo(AWinControl).WantTabs);
   Result := TLCLIntfHandle(scr);
 end;
 
@@ -1457,7 +1457,7 @@ var
 begin
   txt := GetTextView(ACustomMemo);
   if (not Assigned(txt)) then Exit;
-  txt.allowTabs := NewWantTabs;
+  txt.callback.SetTabSuppress(not NewWantTabs);
 end;
 
 class procedure  TCocoaWSCustomMemo.SetWordWrap(const ACustomMemo: TCustomMemo; const NewWordWrap: boolean);