{
/***************************************************************************
                             CodeContextForm.pas
                             -------------------

 ***************************************************************************/

 ***************************************************************************
 *                                                                         *
 *   This source is free software; you can redistribute it and/or modify   *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This code is distributed in the hope that it will be useful, but      *
 *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
 *   General Public License for more details.                              *
 *                                                                         *
 *   A copy of the GNU General Public License is available on the World    *
 *   Wide Web at <http://www.gnu.org/copyleft/gpl.html>. You can also      *
 *   obtain it by writing to the Free Software Foundation,                 *
 *   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.        *
 *                                                                         *
 ***************************************************************************

  Author: Mattias Gaertner
  
  Abstract:
    The popup tooltip window for the source editor.
    For example for the parameter hints.
}
unit CodeContextForm;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Types, LCLProc, LResources, Forms, Controls,
  Graphics, Dialogs, LCLType, LCLIntf, Themes, Buttons, SynEdit, SynEditKeyCmds,
  BasicCodeTools, KeywordFuncLists, LinkScanner, CodeCache, FindDeclarationTool,
  IdentCompletionTool, CodeTree, CodeAtom, PascalParserTool, CodeToolManager,
  SrcEditorIntf, LazIDEIntf, IDEProcs, LazarusIDEStrConsts;

type

  { TCodeContextItem }

  TCodeContextItem = class
  public
    Code: string;
    Hint: string;
    NewBounds: TRect;
    CopyAllButton: TSpeedButton;
    destructor Destroy; override;
  end;

  { TCodeContextFrm }

  TCodeContextFrm = class(THintWindow)
    procedure ApplicationIdle(Sender: TObject; var {%H-}Done: Boolean);
    procedure CopyAllBtnClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure FormPaint(Sender: TObject);
    procedure FormUTF8KeyPress(Sender: TObject; var UTF8Key: TUTF8Char);
    procedure OnSrcEditStatusChange(Sender: TObject);
  private
    FHints: TFPList; // list of TCodeContextItem
    FIdleConnected: boolean;
    FLastParameterIndex: integer;
    FParamListBracketOpenCodeXYPos: TCodeXYPosition;
    FProcNameCodeXYPos: TCodeXYPosition;
    FSourceEditorTopIndex: integer;
    FBtnWidth: integer;
    fDestroying: boolean;
    procedure CreateHints(const CodeContexts: TCodeContextInfo);
    procedure ClearMarksInHints;
    function GetHints(Index: integer): TCodeContextItem;
    procedure MarkCurrentParameterInHints(ParameterIndex: integer); // 0 based
    procedure CalculateHintsBounds;
    procedure DrawHints(var MaxWidth, MaxHeight: Integer; Draw: boolean);
    procedure CompleteParameters(DeclCode: string);
    procedure ClearHints;
    procedure SetIdleConnected(AValue: boolean);
    procedure SetCodeContexts(const CodeContexts: TCodeContextInfo);
  protected
    procedure Notification(AComponent: TComponent; Operation: TOperation);
      override;
  public
    constructor Create(TheOwner: TComponent); override;
    destructor Destroy; override;
    procedure UpdateHints;
    procedure Paint; override;
    property ProcNameCodeXYPos: TCodeXYPosition read FProcNameCodeXYPos;
    property ParamListBracketOpenCodeXYPos: TCodeXYPosition
                                            read FParamListBracketOpenCodeXYPos;
    property SourceEditorTopIndex: integer read FSourceEditorTopIndex;
    property LastParameterIndex: integer read FLastParameterIndex;
    property Hints[Index: integer]: TCodeContextItem read GetHints;
    property IdleConnected: boolean read FIdleConnected write SetIdleConnected;
  end;

var
  CodeContextFrm: TCodeContextFrm = nil;

function ShowCodeContext(Code: TCodeBuffer): boolean;

implementation

type
  TWinControlAccess = class(TWinControl);

function ShowCodeContext(Code: TCodeBuffer): boolean;
var
  LogCaretXY: TPoint;
  CodeContexts: TCodeContextInfo;
begin
  Result := False;
  LogCaretXY := SourceEditorManagerIntf.ActiveEditor.CursorTextXY;
  CodeContexts := nil;
  try
    if not CodeToolBoss.FindCodeContext(Code, LogCaretXY.X, LogCaretXY.Y, CodeContexts) or
      (CodeContexts = nil) or (CodeContexts.Count = 0) then
      Exit;
    if CodeContextFrm = nil then
      CodeContextFrm := TCodeContextFrm.Create(LazarusIDE.OwningComponent);
    CodeContextFrm.DisableAlign;
    try
      CodeContextFrm.SetCodeContexts(CodeContexts);
      CodeContextFrm.Visible := True;
    finally
      CodeContextFrm.EnableAlign;
    end;
    Result := True;
  finally
    CodeContexts.Free;
  end;
end;

{ TCodeContextItem }

destructor TCodeContextItem.Destroy;
begin
  FreeAndNil(CopyAllButton);
  inherited Destroy;
end;

{ TCodeContextFrm }

procedure TCodeContextFrm.ApplicationIdle(Sender: TObject; var Done: Boolean);
begin
  if not Visible then exit;
  UpdateHints;
  IdleConnected:=false;
end;

procedure TCodeContextFrm.CopyAllBtnClick(Sender: TObject);
var
  i: LongInt;
  Item: TCodeContextItem;
begin
  i:=FHints.Count-1;
  while (i>=0) do begin
    Item:=Hints[i];
    if Item.CopyAllButton=Sender then begin
      //debugln(['TCodeContextFrm.CopyAllBtnClick Hint="',Item.Code,'"']);
      CompleteParameters(Item.Code);
      exit;
    end;
    dec(i);
  end;
end;

procedure TCodeContextFrm.FormCreate(Sender: TObject);
begin
  FBtnWidth:=16;
  FHints:=TFPList.Create;
  IdleConnected:=true;
  SourceEditorManagerIntf.RegisterChangeEvent(semEditorStatus,@OnSrcEditStatusChange);
end;

procedure TCodeContextFrm.FormDestroy(Sender: TObject);
begin
  if SourceEditorManagerIntf<>nil then
    SourceEditorManagerIntf.UnregisterChangeEvent(semEditorStatus,@OnSrcEditStatusChange);
  IdleConnected:=false;
  ClearHints;
  FreeAndNil(FHints);
end;

procedure TCodeContextFrm.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
var
  SrcEdit: TSourceEditorInterface;
begin
  if (Key=VK_ESCAPE) and (Shift=[]) then
    Hide
  else if SourceEditorManagerIntf<>nil then begin
    SrcEdit:=SourceEditorManagerIntf.ActiveEditor;
    if SrcEdit=nil then
      Hide
    else begin
      // redirect keys
      TWinControlAccess(SrcEdit.EditorControl).KeyDown(Key,Shift);
      SetActiveWindow(SourceEditorManagerIntf.ActiveSourceWindow.Handle);
    end;
  end;
end;

procedure TCodeContextFrm.FormPaint(Sender: TObject);
var
  DrawWidth: LongInt;
  DrawHeight: LongInt;
begin
  DrawWidth:=ClientWidth;
  DrawHeight:=ClientHeight;
  DrawHints(DrawWidth,DrawHeight,true);
end;

procedure TCodeContextFrm.FormUTF8KeyPress(Sender: TObject;
  var UTF8Key: TUTF8Char);
var
  SrcEdit: TSourceEditorInterface;
  ASynEdit: TCustomSynEdit;
begin
  SrcEdit:=SourceEditorManagerIntf.ActiveEditor;
  if SrcEdit=nil then begin
    Hide;
  end else begin
    ASynEdit:=(SrcEdit.EditorControl as TCustomSynEdit);
    ASynEdit.CommandProcessor(ecChar,UTF8Key,nil);
  end;
end;

procedure TCodeContextFrm.OnSrcEditStatusChange(Sender: TObject);
begin
  IdleConnected:=true;
end;

procedure TCodeContextFrm.SetCodeContexts(const CodeContexts: TCodeContextInfo);
begin
  FillChar(FProcNameCodeXYPos,SizeOf(FProcNameCodeXYPos),0);
  FillChar(FParamListBracketOpenCodeXYPos,SizeOf(FParamListBracketOpenCodeXYPos),0);

  if CodeContexts<>nil then begin
    if (CodeContexts.ProcNameAtom.StartPos>0) then begin
      CodeContexts.Tool.MoveCursorToCleanPos(CodeContexts.ProcNameAtom.StartPos);
      CodeContexts.Tool.CleanPosToCaret(CodeContexts.Tool.CurPos.StartPos,
                                        FProcNameCodeXYPos);
      CodeContexts.Tool.ReadNextAtom;// read proc name
      CodeContexts.Tool.ReadNextAtom;// read bracket open
      if CodeContexts.Tool.CurPos.Flag
        in [cafRoundBracketOpen,cafEdgedBracketOpen]
      then begin
        CodeContexts.Tool.CleanPosToCaret(CodeContexts.Tool.CurPos.StartPos,
                                          FParamListBracketOpenCodeXYPos);
      end;
    end;
  end;
  
  CreateHints(CodeContexts);
  CalculateHintsBounds;
end;

procedure TCodeContextFrm.UpdateHints;
var
  SrcEdit: TSourceEditorInterface;
  CurTextXY: TPoint;
  ASynEdit: TSynEdit;
  NewParameterIndex: Integer;
  BracketPos: TPoint;
  Line: string;
  Code: String;
  TokenEnd: LongInt;
  TokenStart: LongInt;
  KeepOpen: Boolean;
  BracketLevel: Integer;
  i: Integer;
  Item: TCodeContextItem;
begin
  if not Visible then exit;
  
  KeepOpen:=false;
  NewParameterIndex:=-1;
  try
    if not Application.Active then exit;

    // check Source Editor
    if SourceEditorManagerIntf=nil then exit;
    SrcEdit:=SourceEditorManagerIntf.ActiveEditor;
    if (SrcEdit=nil) or (SrcEdit.CodeToolsBuffer<>ProcNameCodeXYPos.Code) then
      exit;
    if SrcEdit.TopLine<>FSourceEditorTopIndex then exit;

    CurTextXY:=SrcEdit.CursorTextXY;
    BracketPos:=Point(ParamListBracketOpenCodeXYPos.X,
                      ParamListBracketOpenCodeXYPos.Y);
    if ComparePoints(CurTextXY,BracketPos)<=0 then begin
      // cursor moved in front of parameter list
      exit;
    end;

    // find out, if cursor is in procedure call and where
    ASynEdit:=SrcEdit.EditorControl as TSynEdit;

    Line:=ASynEdit.Lines[BracketPos.Y-1];
    if (length(Line)<BracketPos.X) or (not (Line[BracketPos.X] in ['(','[']))
    then begin
      // bracket lost -> something changed -> hints became invalid
      exit;
    end;
    
    // collect the lines from bracket open to cursor
    Code:=StringListPartToText(ASynEdit.Lines,BracketPos.Y-1,CurTextXY.Y-1,#10);
    if CurTextXY.Y<=ASynEdit.Lines.Count then begin
      Line:=ASynEdit.Lines[CurTextXY.Y-1];
      if length(Line)>=CurTextXY.X then
        SetLength(Code,length(Code)-length(Line)+CurTextXY.X-1);
    end;
    //DebugLn('TCodeContextFrm.UpdateHints Code="',DbgStr(Code),'"');

    // parse the code
    TokenEnd:=BracketPos.X;
    BracketLevel:=0;
    repeat
      ReadRawNextPascalAtom(Code,TokenEnd,TokenStart);
      if TokenEnd=TokenStart then break;
      case Code[TokenStart] of
      '(','[':
        begin
          inc(BracketLevel);
          if BracketLevel=1 then
            NewParameterIndex:=0;
        end;
      ')',']':
        begin
          dec(BracketLevel);
          if BracketLevel=0 then exit;// cursor behind procedure call
        end;
      ',':
        if BracketLevel=1 then inc(NewParameterIndex);
      else
        if IsIdentStartChar[Code[TokenStart]] then begin
          if CompareIdentifiers(@Code[TokenStart],'end')=0 then
            break;// cursor behind procedure call
        end;
      end;
    until false;
    KeepOpen:=true;

    // show buttons
    for i:=0 to FHints.Count-1 do begin
      Item:=TCodeContextItem(FHints[i]);
      if Item.CopyAllButton <> nil then begin
        Item.CopyAllButton.BoundsRect:=Item.NewBounds;
        Item.CopyAllButton.Visible:=Item.NewBounds.Right>0;
      end;
    end;
  finally
    if not KeepOpen then
      Hide
    else if NewParameterIndex<>LastParameterIndex then
      MarkCurrentParameterInHints(NewParameterIndex);
  end;
end;

procedure TCodeContextFrm.CreateHints(const CodeContexts: TCodeContextInfo);

  function FindBaseType(Tool: TFindDeclarationTool; Node: TCodeTreeNode;
    var s: string): boolean;
  var
    Expr: TExpressionType;
    Params: TFindDeclarationParams;
    ExprTool: TFindDeclarationTool;
    ExprNode: TCodeTreeNode;
  begin
    Result:=false;
    Params:=TFindDeclarationParams.Create(Tool, Node);
    try
      try
        Expr:=Tool.ConvertNodeToExpressionType(Node,Params);
        //debugln(['FindBaseType ',s,' ',ExprTypeToString(Expr)]);
        if (Expr.Desc=xtContext) and (Expr.Context.Node<>nil) then begin
          ExprTool:=Expr.Context.Tool;
          ExprNode:=Expr.Context.Node;
          case ExprNode.Desc of
          ctnProcedureType:
            begin
              s:=s+ExprTool.ExtractProcHead(ExprNode,
                 [phpWithVarModifiers,phpWithParameterNames,phpWithDefaultValues,
                 phpWithResultType]);
              Result:=true;
            end;
          ctnOpenArrayType:
            begin
              s:=s+'[Index: PtrUInt]';
              Result:=true;
            end;
          ctnRangedArrayType:
            begin
              s:=s+ExprTool.ExtractArrayRange(ExprNode,[]);
              Result:=true;
            end;
          end;
        end else if Expr.Desc in (xtAllStringTypes+xtAllWideStringTypes-[xtShortString])
        then begin
          s:=s+'[Index: 1..high(PtrUInt)]';
          Result:=true;
        end else if Expr.Desc=xtShortString then begin
          s:=s+'[Index: 0..255]';
          Result:=true;
        end;
        if not Result then
          debugln(['TCodeContextFrm.CreateHints.FindBaseType: not yet supported: ',ExprTypeToString(Expr)]);
      except
      end;
    finally
      Params.Free;
    end;
  end;

var
  i: Integer;
  CurExprType: TExpressionType;
  CodeNode: TCodeTreeNode;
  CodeTool: TFindDeclarationTool;
  s: String;
  p: Integer;
  CurContext: TCodeContextInfoItem;
  Btn: TSpeedButton;
  j: Integer;
  Code: String;
  Item: TCodeContextItem;
begin
  ClearHints;
  if (CodeContexts=nil) or (CodeContexts.Count=0) then exit;
  for i:=0 to CodeContexts.Count-1 do begin
    CurContext:=CodeContexts[i];
    CurExprType:=CurContext.Expr;
    Code:=ExpressionTypeDescNames[CurExprType.Desc];
    if CurExprType.Context.Node<>nil then begin
      CodeNode:=CurExprType.Context.Node;
      CodeTool:=CurExprType.Context.Tool;
      case CodeNode.Desc of
      ctnProcedure:
        begin
          Code:=CodeTool.ExtractProcHead(CodeNode,
              [phpWithVarModifiers,phpWithParameterNames,phpWithDefaultValues,
               phpWithResultType]);
        end;
      ctnProperty:
        begin
          if CodeTool.PropertyNodeHasParamList(CodeNode) then begin
            Code:=CodeTool.ExtractProperty(CodeNode,
                [phpWithVarModifiers,phpWithParameterNames,phpWithDefaultValues,
                 phpWithResultType]);
          end else if not CodeTool.PropNodeIsTypeLess(CodeNode) then begin
            Code:=CodeTool.ExtractPropName(CodeNode,false);
            if not FindBaseType(CodeTool,CodeNode,Code) then
              continue;
          end else begin
            // ignore properties without type
            continue;
          end;
        end;
      ctnVarDefinition:
        begin
          Code:=CodeTool.ExtractDefinitionName(CodeNode);
          if not FindBaseType(CodeTool,CodeNode,Code) then
            continue; // ignore normal variables
        end;
      end;
    end else if CurContext.Params<>nil then begin
      // compiler function
      Code:=CurContext.ProcName+'('+CurContext.Params.DelimitedText+')';
      if CurContext.ResultType<>'' then
        Code:=Code+':'+CurContext.ResultType;
    end;
    // insert spaces
    for p:=length(Code)-1 downto 1 do begin
      if (Code[p] in [',',';',':']) and (Code[p+1]<>' ') then
        System.Insert(' ',Code,p+1);
    end;
    Code:=Trim(Code);
    s:=Code;
    // mark the mark characters
    for p:=length(s) downto 1 do
      if s[p]='\' then
        System.Insert('\',s,p+1);
    // add hint if not already exists
    j:=FHints.Count-1;
    while (j>=0) and (CompareText(Hints[j].Code,Code)<>0) do
      dec(j);
    if j<0 then begin
      Item:=TCodeContextItem.Create;
      Item.Code:=Code;
      Item.Hint:=s;
      Btn:=TSpeedButton.Create(Self);
      Item.CopyAllButton:=Btn;
      Btn.Name:='CopyAllSpeedButton'+IntToStr(i+1);
      Btn.OnClick:=@CopyAllBtnClick;
      Btn.Visible:=false;
      Btn.LoadGlyphFromResourceName(HInstance, 'laz_copy');
      Btn.Flat:=true;
      Btn.Parent:=Self;
      FHints.Add(Item);
    end;
  end;
  if FHints.Count=0 then begin
    Item:=TCodeContextItem.Create;
    Item.Code:='';
    Item.Hint:=lisNoHints;
    FHints.Add(Item);
  end;
  MarkCurrentParameterInHints(CodeContexts.ParameterIndex-1);
end;

procedure TCodeContextFrm.ClearMarksInHints;
// remove all marks except the \\ marks
var
  i: Integer;
  s: string;
  p: Integer;
  Item: TCodeContextItem;
begin
  for i:=0 to FHints.Count-1 do begin
    Item:=Hints[i];
    s:=Item.Hint;
    p:=1;
    while p<length(s) do begin
      if s[p]<>'\' then
        inc(p)  // normal character
      else if s[p+1]='\' then
        inc(p,2) // '\\'
      else begin
        System.Delete(s,p,2); // remove mark
      end;
    end;
    Item.Hint:=s;
  end;
end;

function TCodeContextFrm.GetHints(Index: integer): TCodeContextItem;
begin
  Result:=TCodeContextItem(FHints[Index]);
end;

procedure TCodeContextFrm.MarkCurrentParameterInHints(ParameterIndex: integer);

  function MarkCurrentParameterInHint(const s: string): string;
  var
    p: Integer;
    CurrentMark: Char;

    procedure Mark(NewMark: char; Position: integer);
    begin
      if p=Position then
        CurrentMark:=NewMark;
      System.Insert('\'+NewMark,Result,Position);
      if Position<=p then
        inc(p,2);
      //DebugLn('Mark Position=',dbgs(Position),' p=',dbgs(p),' CurrentMark="',CurrentMark,'" ',copy(Result,1,Position+2));
    end;
  
  var
    BracketLevel: Integer;
    CurParameterIndex: Integer;
    WordStart: LongInt;
    WordEnd: LongInt;
    ModifierStart: LongInt;
    ModifierEnd: LongInt;
    SearchingType: Boolean;
    ReadingType: Boolean;
  begin
    Result:=s;
    BracketLevel:=0;
    CurParameterIndex:=0;
    CurrentMark:='*';
    ReadingType:=false;
    SearchingType:=false;
    ModifierStart:=-1;
    ModifierEnd:=-1;
    p:=1;
    while (p<=length(Result)) do begin
      //DebugLn('MarkCurrentParameterInHint p=',dbgs(p),' "',Result[p],'" BracketLevel=',dbgs(BracketLevel),' CurParameterIndex=',dbgs(CurParameterIndex),' ReadingType=',dbgs(ReadingType),' SearchingType=',dbgs(SearchingType));
      case Result[p] of
      '(','{','[':
        inc(BracketLevel);
      ')','}',']':
        begin
          if (BracketLevel=1) then begin
            if CurrentMark<>'*' then
              Mark('*',p);
            exit;
          end;
          dec(BracketLevel);
        end;
      ',':
        if BracketLevel=1 then begin
          inc(CurParameterIndex);
        end;
      ':':
        if BracketLevel=1 then begin
          // names ended, type started
          if SearchingType then
            Mark('b',p);
          ReadingType:=true;
          SearchingType:=false;
        end;
      ';':
        if BracketLevel=1 then begin
          // type ended, next parameter started
          if CurrentMark<>'*' then
            Mark('*',p);
          SearchingType:=false;
          ReadingType:=false;
          ModifierStart:=-1;
          inc(CurParameterIndex);
        end;
      '''':
        repeat
          inc(p);
        until (p>=length(Result)) or (Result[p]='''');
      'a'..'z','A'..'Z','_':
        if (BracketLevel=1) and (not ReadingType) then begin
          WordStart:=p;
          while (p<=length(Result)) and (IsIdentChar[Result[p]]) do
            inc(p);
          WordEnd:=p;
          //DebugLn('MarkCurrentParameterInHint Word=',copy(Result,WordStart,WordEnd-WordStart));
          if (CompareIdentifiers('const',@Result[WordStart])=0)
          or (CompareIdentifiers('out',@Result[WordStart])=0)
          or (CompareIdentifiers('var',@Result[WordStart])=0) then begin
            // modifier
            ModifierStart:=WordStart;
            ModifierEnd:=WordEnd;
          end else begin
            // parameter name
            if ParameterIndex=CurParameterIndex then begin
              // mark parameter
              Mark('*',WordEnd); // mark WordEnd before WordStart !
              Mark('b',WordStart);
              // mark modifier
              if ModifierStart>0 then begin
                Mark('*',ModifierEnd); // mark ModifierEnd before ModifierStart !
                Mark('b',ModifierStart);
              end;
              // search type
              SearchingType:=true;
            end;
          end;
          dec(p);
        end;
      end;
      inc(p);
    end;
  end;
  
var
  i: Integer;
  Item: TCodeContextItem;
begin
  //DebugLn('TCodeContextFrm.MarkCurrentParameterInHints FLastParameterIndex=',dbgs(FLastParameterIndex),' ParameterIndex=',dbgs(ParameterIndex));
  ClearMarksInHints;
  for i:=0 to FHints.Count-1 do begin
    Item:=Hints[i];
    Item.Hint:=MarkCurrentParameterInHint(Item.Hint);
  end;
  FLastParameterIndex:=ParameterIndex;
  Invalidate;
end;

procedure TCodeContextFrm.CalculateHintsBounds;
var
  DrawWidth: LongInt;
  SrcEdit: TSourceEditorInterface;
  NewBounds: TRect;
  CursorTextXY: TPoint;
  ScreenTextXY: TPoint;
  ClientXY: TPoint;
  DrawHeight: LongInt;
  ScreenXY: TPoint;
begin
  SrcEdit:=SourceEditorManagerIntf.ActiveEditor;
  if SrcEdit=nil then exit;

  // calculate the position of the context in the source editor
  CursorTextXY:=SrcEdit.CursorTextXY;
  if ProcNameCodeXYPos.Code<>nil then begin
    if (ProcNameCodeXYPos.Code=SrcEdit.CodeToolsBuffer)
    and (ProcNameCodeXYPos.Y<=CursorTextXY.Y) then begin
      CursorTextXY:=Point(ProcNameCodeXYPos.X,ProcNameCodeXYPos.Y);
    end;
  end;
  // calculate screen position
  ScreenTextXY:=SrcEdit.TextToScreenPosition(CursorTextXY);
  ClientXY:=SrcEdit.ScreenToPixelPosition(ScreenTextXY);
  ScreenXY:=SrcEdit.EditorControl.ClientToScreen(ClientXY);
  FSourceEditorTopIndex:=SrcEdit.TopLine;

  // calculate size of hints
  DrawWidth:=SourceEditorManagerIntf.ActiveSourceWindow.ClientWidth;
  DrawHeight:=ScreenXY.Y-GetParentForm(SrcEdit.EditorControl).Monitor.WorkareaRect.Top-10;
  DrawHints(DrawWidth,DrawHeight,false);
  if DrawWidth<20 then DrawWidth:=20;
  if DrawHeight<5 then DrawHeight:=5;

  // calculate position of hints in editor client area
  if ClientXY.X+DrawWidth>SrcEdit.EditorControl.ClientWidth then
    ClientXY.X:=SrcEdit.EditorControl.ClientWidth-DrawWidth;
  if ClientXY.X<0 then
    ClientXY.X:=0;
  dec(ClientXY.Y,DrawHeight);

  // calculate screen position
  ScreenXY:=SrcEdit.EditorControl.ClientToScreen(ClientXY);
  NewBounds:=Bounds(ScreenXY.X,ScreenXY.Y-4,DrawWidth,DrawHeight);

  // move form
  BoundsRect:=NewBounds;
end;

procedure TCodeContextFrm.DrawHints(var MaxWidth, MaxHeight: Integer;
  Draw: boolean);
var
  LeftSpace, RightSpace: Integer;
  VerticalSpace: Integer;
  BackgroundColor, TextGrayColor, TextColor, PenColor: TColor;
  TextGrayStyle, TextStyle: TFontStyles;

  procedure DrawHint(Index: integer; var AHintRect: TRect);
  var
    ATextRect: TRect;
    TokenStart: Integer;
    TokenRect: TRect;
    TokenSize: TPoint;
    TokenPos: TPoint;
    TokenEnd: LongInt;
    UsedWidth: Integer; // maximum right token position
    LineHeight: Integer; // current line height
    LastTokenEnd: LongInt;
    Line: string;
    Item: TCodeContextItem;
    y: LongInt;
    r: TRect;
  begin
    Item:=Hints[Index];
    Line:=Item.Hint;
    ATextRect:=Rect(AHintRect.Left+LeftSpace,
                    AHintRect.Top+VerticalSpace,
                    AHintRect.Right-RightSpace,
                    AHintRect.Bottom-VerticalSpace);
    UsedWidth:=0;
    LineHeight:=0;
    TokenPos:=Point(ATextRect.Left,ATextRect.Top);
    TokenEnd:=1;
    while (TokenEnd<=length(Line)) do begin
      LastTokenEnd:=TokenEnd;
      ReadRawNextPascalAtom(Line,TokenEnd,TokenStart);
      if TokenEnd<=LastTokenEnd then break;
      if Line[TokenStart]='\' then begin
        // mark found
        if TokenStart>LastTokenEnd then begin
          // there is a gap between last token and this token -> draw that first
          TokenEnd:=TokenStart;
        end else begin
          inc(TokenStart);
          if TokenStart>length(Line) then break;
          TokenEnd:=TokenStart+1;
          // the token is a mark
          case Line[TokenStart] of
          
          '*':
            begin
              // switch to normal font
              if Draw then begin
                Canvas.Font.Color:=TextGrayColor;
                Canvas.Font.Style:=TextGrayStyle;
              end;
              //DebugLn('DrawHint gray');
              continue;
            end;
            
          'b':
            begin
              // switch to normal font
              if Draw then begin
                Canvas.Font.Color:=TextColor;
                Canvas.Font.Style:=TextStyle;
              end;
              //DebugLn('DrawHint normal');
              continue;
            end;
            
          else
            // the token is a normal character -> paint it
          end;
        end;
      end;
      //DebugLn('DrawHint Token="',copy(Line,TokenStart,TokenEnd-TokenStart),'"');
      
      // calculate token size
      TokenRect:=Bounds(0,0,12345,1234);
      DrawText(Canvas.Handle,@Line[LastTokenEnd],TokenEnd-LastTokenEnd,TokenRect,
               DT_SINGLELINE+DT_CALCRECT+DT_NOCLIP);
      TokenSize:=Point(TokenRect.Right,TokenRect.Bottom);
      {$IFDEF EnableCCFFontMin}
      // workaround for bug 22190
      if TokenSize.y<14 then TokenSize.y:=14;
      {$ENDIF}
      //DebugLn(['DrawHint Draw="',Draw,'" Token="',copy(Line,TokenStart,TokenEnd-TokenStart),'" TokenSize=',dbgs(TokenSize)]);

      if (LineHeight>0) and (TokenPos.X+TokenRect.Right>ATextRect.Right) then
      begin
        // token does not fit into line -> break line
        // fill end of line
        if Draw and (TokenPos.X<AHintRect.Right) then begin
          Canvas.FillRect(Rect(TokenPos.X,TokenPos.Y-VerticalSpace,
                          AHintRect.Right,TokenPos.Y+LineHeight+VerticalSpace));
        end;
        TokenPos:=Point(ATextRect.Left,TokenPos.y+LineHeight+VerticalSpace);
        LineHeight:=0;
      end;

      // token fits into line
      // => draw token
      OffsetRect(TokenRect,TokenPos.x,TokenPos.y);
      if Draw then begin
        Canvas.FillRect(Rect(TokenRect.Left,TokenRect.Top-VerticalSpace,
                             TokenRect.Right,TokenRect.Bottom+VerticalSpace));
        DrawText(Canvas.Handle,@Line[LastTokenEnd],TokenEnd-LastTokenEnd,
                 TokenRect,DT_SINGLELINE+DT_NOCLIP);
      end;
      // update LineHeight and UsedWidth
      if LineHeight<TokenSize.y then
        LineHeight:=TokenSize.y;
      inc(TokenPos.X,TokenSize.x);
      if UsedWidth<TokenPos.X then
        UsedWidth:=TokenPos.X;
    end;
    // fill end of line
    if Draw and (TokenPos.X<AHintRect.Right) and (LineHeight>0) then begin
      Canvas.FillRect(Rect(TokenPos.X,TokenPos.Y-VerticalSpace,
                      AHintRect.Right,TokenPos.Y+LineHeight+VerticalSpace));
    end;

    if (not Draw) and (UsedWidth>0) then
      AHintRect.Right:=UsedWidth+RightSpace;
    AHintRect.Bottom:=TokenPos.Y+LineHeight+VerticalSpace;

    if Draw and (Item.CopyAllButton<>nil) then begin
      // move button at end of first line
      y:=ATextRect.Top;
      if LineHeight>FBtnWidth then
        inc(y,(LineHeight-FBtnWidth) div 2);
      Item.NewBounds:=Bounds(AHintRect.Right-RightSpace-1,y,FBtnWidth,FBtnWidth);
      r:=Item.CopyAllButton.BoundsRect;
      if not CompareRect(@r,@Item.NewBounds) then
        IdleConnected:=true;
    end;
    //debugln(['DrawHint ',y,' Line="',dbgstr(Line),'" LineHeight=',LineHeight,' ']);
  end;
  
var
  i: Integer;
  NewMaxHeight: Integer;
  NewMaxWidth: Integer;
  CurHintRect: TRect;
  Details: TThemedElementDetails;
begin
  //DebugLn('TCodeContextFrm.DrawHints DrawWidth=',dbgs(MaxWidth),' DrawHeight=',dbgs(MaxHeight),' Draw=',dbgs(Draw));
  if Draw then begin
    // make colors theme dependent
    BackgroundColor:=clInfoBk;
    TextGrayColor:=clInfoText;
    TextGrayStyle:=[];
    TextColor:=clInfoText;
    TextStyle:=[fsBold];
    PenColor:=clBlack;
  end;
  LeftSpace:=2;
  RightSpace:=2+FBtnWidth;
  VerticalSpace:=2;

  if Draw then begin
    Canvas.Brush.Color:=BackgroundColor;
    Canvas.Font.Color:=TextGrayColor;
    Canvas.Font.Style:=TextGrayStyle;
    Canvas.Pen.Color:=PenColor;
    Details := ThemeServices.GetElementDetails(tttStandardLink);
    ThemeServices.DrawElement(Canvas.Handle, Details, ClientRect);
  end else begin
    Canvas.Font.Style:=[fsBold];
  end;
  NewMaxWidth:=0;
  NewMaxHeight:=0;
  for i:=0 to FHints.Count-1 do begin
    if Draw and (NewMaxHeight>=MaxHeight) then break;
    CurHintRect:=Rect(0,NewMaxHeight,MaxWidth,MaxHeight);
    DrawHint(i,CurHintRect);
    if CurHintRect.Right>NewMaxWidth then
      NewMaxWidth:=CurHintRect.Right;
    NewMaxHeight:=CurHintRect.Bottom;
  end;
  // for fractionals add some space
  inc(NewMaxWidth,2);
  inc(NewMaxHeight,2);
  // add space for the copy all button
  inc(NewMaxWidth,16);

  if Draw then begin
    // fill rest of form
    if NewMaxHeight<MaxHeight then
      Canvas.FillRect(Rect(0,NewMaxHeight,MaxWidth,MaxHeight));
    // draw frame around window
    Canvas.Frame(Rect(0,0,MaxWidth-1,MaxHeight-1));
  end;
  if not Draw then begin
    // adjust max width and height
    if NewMaxWidth<MaxWidth then
      MaxWidth:=NewMaxWidth;
    if NewMaxHeight<MaxHeight then
      MaxHeight:=NewMaxHeight;
  end;
end;

procedure TCodeContextFrm.CompleteParameters(DeclCode: string);
// add the parameter names in the source editor

  function ReadNextAtom(ASynEdit: TSynEdit; var TokenLine, TokenEnd: integer;
    out TokenStart: integer): string;
  var
    Line: string;
  begin
    while TokenLine<=ASynEdit.Lines.Count do begin
      Line:=ASynEdit.Lines[TokenLine-1];
      ReadRawNextPascalAtom(Line,TokenEnd,TokenStart);
      if TokenStart<TokenEnd then begin
        Result:=copy(Line,TokenStart,TokenEnd-TokenStart);
        exit;
      end;
      inc(TokenLine);
      TokenEnd:=1;
    end;
    TokenStart:=TokenEnd;
    Result:='';
  end;

  procedure AddParameters(ASynEdit: TSynEdit; Y, X: integer; AddComma: boolean;
    StartIndex: integer);
  var
    NewCode: String;
    TokenStart: Integer;
    BracketLevel: Integer;
    ParameterIndex: Integer;
    TokenEnd: integer;
    LastToken: String;
    Indent: LongInt;
    XY: TPoint;
  begin
    TokenEnd:=1;
    BracketLevel:=0;
    ParameterIndex:=-1;
    NewCode:='';
    LastToken:='';
    repeat
      ReadRawNextPascalAtom(DeclCode,TokenEnd,TokenStart);
      if TokenEnd=TokenStart then break;
      case DeclCode[TokenStart] of
      '(','[':
        begin
          inc(BracketLevel);
          if BracketLevel=1 then
            ParameterIndex:=0;
        end;
      ')',']':
        begin
          dec(BracketLevel);
          if BracketLevel=0 then begin
            // closing bracket found
            break;
          end;
        end;
      ',',':':
        if BracketLevel=1 then begin
          if (LastToken<>'') and (IsIdentStartChar[LastToken[1]])
          and (ParameterIndex>=StartIndex) then begin
            // add parameter
            if AddComma then
              NewCode:=NewCode+',';
            NewCode:=NewCode+LastToken;
            AddComma:=true;
          end;
          if DeclCode[TokenStart]=',' then
            inc(ParameterIndex);
        end;
      ';':
        if BracketLevel=1 then
          inc(ParameterIndex);
      else

      end;
      LastToken:=copy(DeclCode,TokenStart,TokenEnd-TokenStart);
    until false;
    if NewCode='' then exit;
    // format insertion
    Indent:=GetLineIndentWithTabs(ASynEdit.Lines[Y-1],X,ASynEdit.TabWidth);
    if Y<>FParamListBracketOpenCodeXYPos.Y then
      dec(Indent,CodeToolBoss.SourceChangeCache.BeautifyCodeOptions.Indent);
    NewCode:=CodeToolBoss.SourceChangeCache.BeautifyCodeOptions.BeautifyStatement(
      NewCode,Indent,[],X);
    NewCode:=copy(NewCode,Indent+1,length(NewCode));
    if NewCode='' then begin
      ShowMessage(lisAllParametersOfThisFunctionAreAlreadySetAtThisCall);
      exit;
    end;
    // insert
    ASynEdit.BeginUndoBlock{$IFDEF SynUndoDebugBeginEnd}('TCodeContextFrm.CompleteParameters'){$ENDIF};
    try
      XY:=Point(X,Y);
      ASynEdit.BlockBegin:=XY;
      ASynEdit.BlockEnd:=XY;
      ASynEdit.LogicalCaretXY:=XY;
      ASynEdit.SelText:=NewCode;
    finally
      ASynEdit.EndUndoBlock{$IFDEF SynUndoDebugBeginEnd}('TCodeContextFrm.CompleteParameters'){$ENDIF};
    end;
  end;

var
  SrcEdit: TSourceEditorInterface;
  BracketPos: TPoint;
  ASynEdit: TSynEdit;
  Line: string;
  TokenLine, TokenEnd, TokenStart: LongInt;
  LastTokenLine, LastTokenEnd: LongInt;
  BracketLevel: Integer;
  ParameterIndex: Integer;
  Token: String;
  LastToken: String;
  NeedComma: Boolean;
begin
  SrcEdit:=SourceEditorManagerIntf.ActiveEditor;
  if (SrcEdit=nil) or (SrcEdit.CodeToolsBuffer<>ProcNameCodeXYPos.Code) then
    exit;
  BracketPos:=Point(ParamListBracketOpenCodeXYPos.X,
                    ParamListBracketOpenCodeXYPos.Y);
  // find out, if cursor is in procedure call and where
  ASynEdit:=SrcEdit.EditorControl as TSynEdit;

  Line:=ASynEdit.Lines[BracketPos.Y-1];
  if (length(Line)<BracketPos.X) or (not (Line[BracketPos.X] in ['(','[']))
  then begin
    // bracket lost -> something changed -> hints became invalid
    exit;
  end;

  // parse the code
  TokenLine:=BracketPos.Y;
  TokenEnd:=BracketPos.X;
  //debugln(['TCodeContextFrm.CompleteParameters START BracketPos=',dbgs(BracketPos)]);
  TokenStart:=TokenEnd;
  BracketLevel:=0;
  ParameterIndex:=-1;
  Token:='';
  repeat
    LastTokenLine:=TokenLine;
    LastTokenEnd:=TokenEnd;
    LastToken:=Token;
    Token:=ReadNextAtom(ASynEdit,TokenLine,TokenEnd,TokenStart);
    //debugln(['TCodeContextFrm.CompleteParameters Token="',Token,'" ParameterIndex=',ParameterIndex]);
    if TokenEnd=TokenStart then break;
    case Token[1] of
    '(','[':
      begin
        inc(BracketLevel);
        if BracketLevel=1 then
          ParameterIndex:=0;
      end;
    ')',']':
      begin
        dec(BracketLevel);
        if BracketLevel=0 then begin
          // closing bracket found
          NeedComma:=(LastToken<>',') and (LastToken<>'(') and (LastToken<>'[');
          if NeedComma then inc(ParameterIndex);
          //debugln(['TCodeContextFrm.CompleteParameters y=',LastTokenLine,' x=',LastTokenEnd,' ParameterIndex=',ParameterIndex]);
          AddParameters(ASynEdit,LastTokenLine,LastTokenEnd,NeedComma,ParameterIndex);
          break;
        end;
      end;
    ',':
      if BracketLevel=1 then inc(ParameterIndex);
    ';':
      break; // missing close bracket => cursor behind procedure call
    else
      if IsIdentStartChar[Token[1]] then begin
        if CompareIdentifiers(PChar(Token),'end')=0 then
          break;// missing close bracket => cursor behind procedure call
      end;
    end;
  until false;

end;

procedure TCodeContextFrm.ClearHints;
var
  i: Integer;
begin
  for i:=0 to FHints.Count-1 do
    FreeAndNil(Hints[i].CopyAllButton);
  for i:=0 to FHints.Count-1 do
    TObject(FHints[i]).Free;
  FHints.Clear;
end;

procedure TCodeContextFrm.SetIdleConnected(AValue: boolean);
begin
  if fDestroying then AValue:=false;
  if FIdleConnected=AValue then Exit;
  FIdleConnected:=AValue;
  if IdleConnected then
    Application.AddOnIdleHandler(@ApplicationIdle)
  else
    Application.RemoveOnIdleHandler(@ApplicationIdle);
end;

procedure TCodeContextFrm.Notification(AComponent: TComponent;
  Operation: TOperation);
var
  i: Integer;
begin
  inherited Notification(AComponent, Operation);
  if Operation=opRemove then
  begin
    if FHints<>nil then
      for i:=0 to FHints.Count-1 do
        if Hints[i].CopyAllButton=AComponent then
          Hints[i].CopyAllButton:=nil;
  end;
end;

procedure TCodeContextFrm.Paint;
begin
  FormPaint(Self);
end;

constructor TCodeContextFrm.Create(TheOwner: TComponent);
begin
  inherited Create(TheOwner);
  OnDestroy:=@FormDestroy;
  OnKeyDown:=@FormKeyDown;
  OnUTF8KeyPress:=@FormUTF8KeyPress;
  FormCreate(Self);
end;

destructor TCodeContextFrm.Destroy;
begin
  fDestroying:=true;
  IdleConnected:=false;
  if CodeContextFrm=Self then
    CodeContextFrm:=nil;
  inherited Destroy;
end;

end.