wwcalculator.pas

一套及时通讯的原码

          Alignment := taLeftJustify;
          Font.Height := self.Font.Height;
          Font.Name := self.Font.Name;
          Font.Style := self.Font.Style;
       end;
    end;
    FStatusBevel.SetBounds(5, Height-5-btnHeight, Width-10,btnHeight);
    FStatusLabel.SetBounds(9, Height-5-btnHeight+((BtnHeight-FMemoryStatus.Canvas.textheight('M'))div 2), Width-16,btnHeight-4);
  end
  else if not (cboShowStatus in Options) then begin
    if FStatusBevel <> nil then begin
       FStatusBevel.Visible := False;
       FStatusBevel.SetBounds(5, Height-5-FStatusBevel.height, 0,0);
       FStatusBevel.Free;
       FStatusBevel := nil;
    end;
    if FStatusLabel <> nil then begin
       FStatusLabel.Visible := False;
       FStatusLabel.SetBounds(7, Height-5-btnHeight+2,0,0);
       FStatusLabel.Free;
       FStatusLabel := nil;
    end;
  end;

  FullRepaint;
end;

procedure TwwCalculator.WMEraseBkgnd(var Message: TWmEraseBkgnd);
begin
  Message.result:= 1;
end;

Procedure TwwCalculator.Reset; {Clear everything out}
begin
    FCurrentValue := 0.0;

    FResultEdit.Text := '0';
    FDecimalEntered:=False;
    FResultValue:=0.0;
    if FStatusLabel <> nil then FStatusLabel.Caption:='';
    FClearOnNextKey:=false;
    FLastOp:=btNone;
    FNextToLastOp:=btNone;
    FLastStatus:='';
    FLastOperatorEquals := false;
    FLastOperand:=0.0;
end;

procedure TwwCalculator.Compute(Sender: TObject);
begin
  DoCalc(TwwCalcButtonType(TSpeedButton(Sender).Tag));
end;

procedure TwwCalculator.DoCalc(ButtonType:TwwCalcButtonType);
const
  MemoryStoreMap: array [Boolean] of string = (' M','');
var
  Temp: string;
  TempValue: Double;
  flag:boolean;
begin
  try
   case ButtonType of
    bt0..bt9:
     begin
        if FClearOnNextKey then begin
           if FLastOperatorEquals then Reset
           else FResultEdit.Text := '0';
        end;
        FClearOnNextKey := false;

        if (FResultEdit.Text = '0') or (FCurrentValue = 0) then
           FResultEdit.Text := '';
        FBackSpaceValid := True;
        FResultEdit.Text := FResultEdit.Text + Btns[ButtonType].Caption;
        FCurrentValue := StrToFloat(FResultEdit.Text);
        if (FStatusLabel <> nil) then
           FStatusLabel.Caption:=FStatusLabel.Caption+OpToChar(ButtonType);
     end;

    btDecimal:
     begin
        if FClearOnNextKey then Reset;
        If not FDecimalEntered then begin
           FCurrentValue := StrToFloat(FResultEdit.Text);
           FResultEdit.Text := FResultEdit.Text + Btns[ButtonType].Caption;
           if (FStatusLabel <> nil) then
              FStatusLabel.Caption:=FStatusLabel.Caption+OpToChar(ButtonType);
           FDecimalEntered:=true;
        end
        else Beep;
     end;

    btPlusMinus:
     begin
      FCurrentValue := StrToFloat(FResultEdit.Text) * -1;
      FResultEdit.Text := FloatToStr(FCurrentValue);
      if FStatusLabel <> nil then begin
         if FClearOnNextKey then
           FStatusLabel.Caption := '0'
         else
           FStatusLabel.Caption := FLastStatus+FResultEdit.Text;
      end;
     end;

    btClearAll:
     begin
      Reset;
     end;

    btClear:
     begin
      FCurrentValue := 0;
      FResultEdit.Text := '0';
      if FStatusLabel <> nil then begin
         if FClearOnNextKey then
           FStatusLabel.Caption := '0'
         else
           FStatusLabel.Caption := FLastStatus;
      end;
     end;

    btPercent,btAdd,btSubtract,btDivide,btMultiply,btEquals:
     begin
       TempValue := StrToFloat(FResultEdit.Text);

       if (Length(FResultEdit.Text) > 0) and (ButtonType <> btEquals) then begin
          if (FLastOperatorEquals) then begin
              FLastOperand := TempValue;
              FLastOp := ButtonType;
              FLastOperatorEquals := False;
              if FStatusLabel <> nil then
                 FStatusLabel.Caption:=FLastStatus+OpToChar(ButtonType);
              FLastStatus := FStatusLabel.Caption;
              FCurrentValue := 0;
          end
          else if not(FLastOp in [btMultiply,btDivide,btAdd,btSubtract,btPercent]) then
          begin
             FLastOperand := TempValue;
             FLastOp := ButtonType;
             FResultValue:=tempvalue;
             if FStatusLabel <> nil then
                FStatusLabel.Caption:=FStatusLabel.Caption+OpToChar(ButtonType);
             FLastStatus := FStatusLabel.Caption;
             FCurrentValue := 0;
          end
          else if (FLastOp in [btMultiply,btDivide,btAdd,btSubtract]) then begin
             if ButtonType = btPercent then begin
                fResultValue := (fResultValue * TempValue)/100.0;
                fLastOperand := TempValue;
             end
             else begin
               case FLastOp of
                 btMultiply: fResultValue := fResultValue * TempValue;
                 btDivide: fResultValue := fResultValue / TempValue;
                 btAdd: fResultValue := fResultValue + TempValue;
                 btSubtract: fResultValue := fResultValue - TempValue;
               end;
               FLastOperand := TempValue;
             end;

             if (FStatusLabel <> nil) then begin
                If ((ButtonType = btMultiply) or (ButtonType=btDivide))
                  and ((FLastOp = btAdd) or (FLastOp=btSubtract)) then
                      FStatusLabel.Caption:='('+FStatusLabel.Caption+')';

                FStatusLabel.Caption := FStatusLabel.Caption+OpToChar(ButtonType);
                FLastStatus := FStatusLabel.Caption;
                if ButtonType = btPercent then begin
                   FLastStatus := FStatusLabel.Caption;
                   FStatusLabel.Caption := FlastStatus+OpToChar(btEquals) + FloatToStr(FResultValue);
                end;
             end;
             FCurrentValue := 0;
          end;

          FLastOp:=ButtonType;
          FResultEdit.Text := FloatToStr(FResultValue);
          FCurrentValue := 0;
       end
       else if (Length(FResultEdit.Text) > 0)then begin
          if FLastOperatorEquals or (FLastOp = btPercent) then TempValue := FLastOperand
          else FLastOperand := TempValue;

          case FLastOp of
            btPercent: fResultValue := (fResultValue * FLastOperand)/100.0;
            btMultiply: fResultValue := fResultValue * TempValue;
            btDivide: fResultValue := fResultValue / TempValue;
            btAdd: fResultValue := fResultValue + TempValue;
            btSubtract: fResultValue := fResultValue - TempValue;
          end;

          if StatusLabel <> nil then begin
             if FLastOperatorEquals then begin
                FStatusLabel.Caption := FLastStatus;
                FStatusLabel.Caption := FStatusLabel.Caption + OpToChar(FLastOp) + FloatToStr(FLastOperand);
             end
             else if FLastOp = btPercent then begin
                FStatusLabel.Caption := FLastStatus;
                FStatusLabel.Caption:='('+FStatusLabel.Caption+')'+FloatToStr(FLastOperand)+Optochar(btPercent);
             end;
             FStatusLabel.Caption:='('+FStatusLabel.Caption+')';
             FLastStatus := FStatusLabel.Caption;
             FStatusLabel.Caption := FStatusLabel.Caption+OpToChar(ButtonType);
             FStatusLabel.Caption := FStatusLabel.Caption + FloatToStr(FResultValue);
          end;

          FLastOperatorEquals := True;
          FResultEdit.Text := FloatToStr(FResultValue);
          FClearOnNextKey := True;
          FCurrentValue := 0;
       end
       else Beep;
    end;

    btBackSpace:
     if FBackSpaceValid then begin
      Temp := FResultEdit.Text;
      if Temp[Length(Temp)] in ['0'..'9'] then
      begin
        Delete(Temp, Length(Temp),1);
        if Temp = '' then begin
          FBackSpaceValid := False;
          Temp := '0';
        end;
        FCurrentValue := StrToFloat(Temp);
        FResultEdit.Text := FloatToStr(FCurrentValue);
        if FStatusLabel <> nil then begin
           Temp := FStatusLabel.Caption;
           Delete(Temp, Length(Temp),1);
           FStatusLabel.Caption := Temp;
        end;
      end
      else begin
        if FStatusLabel <> nil then begin
           Temp := FStatusLabel.Caption;
           if Temp[Length(Temp)] = DecimalSeparator then begin
              FDecimalEntered := False;
              Delete(Temp, Length(Temp),1);
              FStatusLabel.Caption := Temp;
           end
           else FBackSpaceValid := False;
        end;
      end;
     end
     else Beep;

    btInverse:
     begin
      FCurrentValue := 1 / StrToFloat(FResultEdit.Text);
      FResultEdit.Text := FloatToStr(FCurrentValue);
      if FStatusLabel <> nil then begin
         if FClearOnNextKey then
           FStatusLabel.Caption := '0'
         else
           FStatusLabel.Caption := FLastStatus+FResultEdit.Text;
      end;
     end;

    btSqrt:
     begin
      FCurrentValue := Sqrt(StrToFloat(FResultEdit.Text));
      FResultEdit.Text := FloatToStr(FCurrentValue);
      if FStatusLabel <> nil then begin
         if FClearOnNextKey then
           FStatusLabel.Caption := '0'
         else
           FStatusLabel.Caption := FLastStatus+FResultEdit.Text;
      end;
     end;

    btMStore:
     begin
      FMemoryValue := StrToFloat(FResultEdit.Text);
      FMemoryValue := FMemoryValue * 1;
      FCurrentValue := 0;
     end;

    btMAdd:
     begin
      TempValue := FMemoryValue;
      FMemoryValue := StrToFloat(FResultEdit.Text);
      FMemoryValue := (FMemoryValue * 1) + TempValue;
     end;

    btMRecall:
     begin
      FResultEdit.Text := FloatToStr(FMemoryValue);
      FCurrentValue := 0;
     end;

    btMClear:
     begin
      FMemoryValue := 0;
     end;

   end;   // case  ButtonType of...

   except
     on E: Exception do begin
      FResultEdit.Text := E.Message;
      Reset;
     end;
   end;


  FMemoryStatus.Caption := MemoryStoreMap[FMemoryValue = 0];
end;

function TwwCalculator.IsBinaryOperator(ButtonType: TwwCalcButtonType):boolean;
begin
 result := False;
 case ButtonType of
 btMultiply,btDivide,btAdd,btSubtract,btEquals: result := True;
 end;
end;

procedure TwwCalculator.SetBackgroundBitmapDrawStyle(Value: TwwCalcBitmapDrawStyle);
begin
   if Value<>FBackgroundBitmapDrawStyle then
   begin
      FBackgroundBitmapDrawStyle:= Value;
      FullRepaint;
   end
end;

procedure TwwCalculator.SetBackgroundBitmap(Value: TPicture);
var i:integer;
begin
   if (Value = nil) or (Value.Graphic=nil) or Value.Graphic.Empty then begin
     for i:= 0 to ControlCount-1 do begin
       if COntrols[i] is TwwCalcButton then
         TwwCalcButton(controls[i]).FTransparent := False;
     end;
   end
   else begin
    for i:= 0 to ControlCount-1 do begin
       if COntrols[i] is TwwCalcButton then
         TwwCalcButton(controls[i]).FTransparent := True;
    end;
   end;
   FBackGroundBitmap.Assign(Value);
   FPaintBitmap.FreeImage;
   InitBitmapsFlag := True;
   FullRepaint;
end;


function TwwCalculator.GetText: string;
begin
  Result := FResultEdit.Text;
end;

procedure TwwCalculator.SetBorder3D(const Value: Boolean);
begin
  if F3D <> Value then begin
    F3D := Value;
    invalidate;
  end;
end;

procedure TwwCalculator.SetText(const Value: string);
begin
  if FResultEdit <> nil then
     FResultEdit.Text := Value;
end;

procedure TwwCalculator.SetOptions(Value: TwwCalcOptions);
var ChangedOptions: TwwCalcOptions;
begin
  if FOptions <> Value then
  begin
    ChangedOptions := (FOptions - Value) + (Value - FOptions);
    FOptions := Value;
    if ChangedOptions <> [] then begin
{       for i:= 0 to ControlCount-1 do begin
         if COntrols[i] is TwwCalcButton then begin
           TwwCalcButton(controls[i]).FOptions := Value;
           if (FBackGroundBitmap <> nil) and (FBackGroundBitmap.Graphic <> nil) and not FBackgroundbitmap.Graphic.empty then
              TwwCalcButton(controls[i]).FTransparent := True
           else TwwCalcButton(controls[i]).FTransparent := False;
         end;
       end;}
       CalcButtons;
       FullRepaint;
    end;
  end;
end;

procedure TwwCalculator.RefreshSummary;
begin
  if StatusLabel <> nil then begin
     FStatusLabel.Caption := 'Calculator';
  end;
end;

procedure TwwCalculator.FullRepaint;
var i:integer;
begin
  InitBitmapsFlag:= True;
  invalidate;
  for i:= 0 to ControlCount-1 do begin
     controls[i].invalidate;
  end;
end;

procedure TwwCalculator.SetMargin(Value: Integer);
begin
  if FMargin <> Value then
  begin
     FMargin := Value;
     CalcButtons;
  end;
end;

procedure TwwCalculator.SetPanelColor(Value: TColor);
var i:integer;
begin
  if FPanelColor <> Value then
  begin
    FPanelColor := Value;
    Color := Value;
    if FMemoryStatus<>nil then
       FMemoryStatus.Color := Value;

    if FMemoryBevel <> nil then
       FMemoryBevel.FColor := Value;

    for i:= 0 to ControlCount-1 do begin
       if COntrols[i] is TwwCalcButton then
         TwwCalcButton(controls[i]).ButtonColor := Value;
    end;

    FullRepaint;
  end;
end;

procedure Register;
begin
  RegisterComponents('Samples', [TwwCalculator]);
end;

end.