From aaf4d4d12fe633a7a549f16702b0fd8db164bd8a Mon Sep 17 00:00:00 2001
From: dmitry <dmitry@lazarus-ide.org>
Date: Sun, 23 Feb 2020 04:04:39 +0000
Subject: [PATCH] cocoa: passing scroll part information, whenever the scroll
 part is known

git-svn-id: trunk@62663 -
---
 lcl/interfaces/cocoa/cocoaprivate.pas   |  2 +-
 lcl/interfaces/cocoa/cocoascrollers.pas | 19 +++----------------
 lcl/interfaces/cocoa/cocoawscommon.pas  | 16 +++++++++++++---
 3 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/lcl/interfaces/cocoa/cocoaprivate.pas b/lcl/interfaces/cocoa/cocoaprivate.pas
index 0b382fee13..a5380764e5 100644
--- a/lcl/interfaces/cocoa/cocoaprivate.pas
+++ b/lcl/interfaces/cocoa/cocoaprivate.pas
@@ -91,7 +91,7 @@ type
     procedure DidResignKeyNotification;
     procedure SendOnChange;
     procedure SendOnTextChanged;
-    procedure scroll(isVert: Boolean; Pos: Integer);
+    procedure scroll(isVert: Boolean; Pos: Integer; AScrollPart: NSScrollerPart = NSScrollerNoPart);
     // non event methods
     function DeliverMessage(Msg: Cardinal; WParam: WParam; LParam: LParam): LResult;
     function GetPropStorage: TStringList;
diff --git a/lcl/interfaces/cocoa/cocoascrollers.pas b/lcl/interfaces/cocoa/cocoascrollers.pas
index e327e5cd54..83dbcd3a93 100644
--- a/lcl/interfaces/cocoa/cocoascrollers.pas
+++ b/lcl/interfaces/cocoa/cocoascrollers.pas
@@ -180,29 +180,16 @@ var
   sz  : Integer;
   dlt : double;
   v   : double;
-//const
-  //WinPageOfs : integer = 64; // this is an "ofset" of the pageInc used in Windows
-                               // so the click on "large" makes two pages overlap
 begin
   Result := false;
   case prt of
     NSScrollerDecrementPage: begin
       adj := -sc.largeInc;
-      if adj = 0 then
-      begin
-        adj := -sc.pageInt;
-        //if (sc.PageInt>WinPageOfs) then
-        //  inc(adj, WinPageOfs);
-      end;
+      if adj = 0 then adj := -sc.pageInt;
     end;
     NSScrollerIncrementPage: begin
       adj := sc.largeInc;
-      if adj = 0 then
-      begin
-        adj := sc.pageInt;
-        //if (sc.PageInt>WinPageOfs) then
-        //  dec(adj, WinPageOfs);
-      end;
+      if adj = 0 then adj := sc.pageInt;
     end;
     NSScrollerDecrementLine: begin
       adj := -sc.smallInc;
@@ -843,7 +830,7 @@ begin
     HandleMouseDown(self, locInWin, prt);
 
   if Assigned(callback) then
-    callback.scroll( not IsHorizontal(), lclPos);
+    callback.scroll(not IsHorizontal(), lclPos, prt);
 end;
 
 function TCocoaScrollBar.IsHorizontal: Boolean;
diff --git a/lcl/interfaces/cocoa/cocoawscommon.pas b/lcl/interfaces/cocoa/cocoawscommon.pas
index 40f19f3ae4..9d369ff901 100644
--- a/lcl/interfaces/cocoa/cocoawscommon.pas
+++ b/lcl/interfaces/cocoa/cocoawscommon.pas
@@ -92,7 +92,7 @@ type
     procedure DidResignKeyNotification; virtual;
     procedure SendOnChange; virtual;
     procedure SendOnTextChanged; virtual; // text controls (like spin) respond to OnChange for this event, but not for SendOnChange
-    procedure scroll(isVert: Boolean; Pos: Integer); virtual;
+    procedure scroll(isVert: Boolean; Pos: Integer; AScrollPart: NSScrollerPart); virtual;
     function DeliverMessage(var Msg): LRESULT; virtual; overload;
     function DeliverMessage(Msg: Cardinal; WParam: WParam; LParam: LParam): LResult; virtual; overload;
     procedure Draw(ControlContext: NSGraphicsContext; const bounds, dirty: NSRect); virtual;
@@ -1329,10 +1329,12 @@ begin
   SendSimpleMessage(Target, CM_TEXTCHANGED);
 end;
 
-procedure TLCLCommonCallback.scroll(isVert: Boolean; Pos: Integer);
+procedure TLCLCommonCallback.scroll(isVert: Boolean; Pos: Integer;
+  AScrollPart: NSScrollerPart);
 var
   LMScroll: TLMScroll;
   b: Boolean;
+  lclCode: Integer;
 begin
   FillChar(LMScroll{%H-}, SizeOf(LMScroll), #0);
   //todo: this should be a part of a parameter
@@ -1344,7 +1346,15 @@ begin
     LMScroll.Msg := LM_HSCROLL;
 
   LMScroll.Pos := Pos;
-  LMScroll.ScrollCode := SB_THUMBPOSITION; //SIF_POS;
+  case AScrollPart of
+    NSScrollerDecrementPage: lclCode := SB_PAGELEFT;
+    NSScrollerIncrementPage: lclCode := SB_PAGERIGHT;
+    NSScrollerDecrementLine: lclCode := SB_LINELEFT;
+    NSScrollerIncrementLine: lclCode := SB_LINERIGHT;
+  else
+    lclCode := SB_THUMBPOSITION;
+  end;
+  LMScroll.ScrollCode := lclCode; //SIF_POS;
 
   LCLMessageGlue.DeliverMessage(Target, LMScroll);
 end;