A Non-Visual Component for Resizing a Form and All It's Controls

By Christian Ebenegger - c.ebenegger@fsp.ch
and Thierry Revillard - thierry.revillard@fsp.ch

Following the idea explained in the paper In the Spirit of Thales - Resizing a Form (www.undu.com) , we have built a non visual component which automatically, when a form is resized, put all its controls in the right position and also resize some of them, like TFrame, TStringGrid, TListView and so on.

unit AutoResize;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ComCtrls, Grids, DBGrids, StdCtrls, ExtCtrls, Buttons;

type
  TAutoResize = class(TComponent)
  private
    { DΘclarations privΘes }
    TabCoord, TabEditBtn, TabCoordFr, TabEditBtnFr : array of array of Variant;
    OldHeight, OldWidth, OldHeightFr, OldWidthFr : Integer;
  protected
    { DΘclarations protΘgΘes }
  public
    { DΘclarations publiques }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure GetFormInfo(Form : TForm);
    procedure ResizeTheF(BForm : TForm);
    procedure GetFrameInfo(BFrame : TFrame);
    procedure ResizeTheFr(BFrame : TFrame);
  published
    { DΘclarations publiΘes }
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Exemples', [TAutoResize]);
end;

constructor TAutoResize.Create(AOwner: TComponent);
begin
  inherited ;
end;

destructor TAutoResize.Destroy;
begin
  inherited ;
end;

procedure TAutoResize.GetFormInfo(Form : TForm);
var
 I, J, K, MaxLine, MaxCol : Integer;
 TheControl, TheJoinControl : TControl;
 TheOwner : TWinControl;
 OK : Boolean;
 RGN : TRect;
 CoordJoin : TPoint;
begin
 OldHeight := Form.ClientHeight;
 OldWidth  := Form.ClientWidth;
 TabCoord := nil;
 TabEditBtn := nil;
 MaxLine := 0;
 K := 0;
  for I := 0 to (Form.ComponentCount - 1) do
   begin
    TheControl := TControl(Form.FindComponent(Form.Components[I].Name));
    if (TheControl is TWinControl) or (TheControl is TGraphicControl) then
     begin
      if (TheControl is TEdit) or (TheControl is TBitBtn) then
       begin
        TheOwner := TheControl.Parent;
        CoordJoin.y := TheControl.Top + 1;
        CoordJoin.x := TheControl.Left + TheControl.Width + 2;
        TheJoinControl := TheOwner.ControlAtPos(CoordJoin, true, true);
        if TheJoinControl <> nil then
         begin
          if (TheJoinControl is TButton) or (TheJoinControl is TBitBtn) or (TheJoinControl is TComboBox) then
           begin
            SetLength(TabEditBtn, K + 1, 2);
            TabEditBtn[K, 0] := TheControl.Name;
            TabEditBtn[K, 1] := TheJoinControl.Name;
            Inc(K, 1);
           end;
         end;
       end;

      RGN := TheControl.BoundsRect;
      OK := False;
      J := 0;
      while OK = False do
       begin
        if TheControl.Parent <> nil then
         begin
          Inc(J,1);
          TheControl := TheControl.Parent;
         end
        else
         OK := True;
       end;
      if J > MaxLine then
       begin
        MaxCol := 0;
        MaxLine := J;
        SetLength(TabCoord, J);
        SetLength(TabCoord[(J - 1)], 5);
       end
      else
       begin
        MaxCol := Length(TabCoord[(J - 1)]);
        SetLength(TabCoord[(J - 1)], (MaxCol + 5));
       end;

      TabCoord[(J - 1), MaxCol] := Form.Components[I].Name;
      TabCoord[(J - 1), (MaxCol + 1)] := RGN.Left;
      TabCoord[(J - 1), (MaxCol + 2)] := RGN.Top;
      TabCoord[(J - 1), (MaxCol + 3)] := RGN.Right;
      TabCoord[(J - 1), (MaxCol + 4)] := RGN.Bottom;
     end;
   end;
end;

procedure TAutoResize.GetFrameInfo(BFrame : TFrame);
var
 I, J, K, MaxLine, MaxCol : Integer;
 TheControl, TheJoinControl : TControl;
 TheOwner : TWinControl;
 OK : Boolean;
 RGN : TRect;
 CoordJoin : TPoint;
begin
 OldHeightFr := BFrame.ClientHeight;
 OldWidthFr  := BFrame.ClientWidth;
 TabCoordFr := nil;
 TabEditBtnFr := nil;
 MaxLine := 0;
 K := 0;

  for I := 0 to (BFrame.ComponentCount - 1) do
   begin
    TheControl := TControl(BFrame.FindComponent(BFrame.Components[I].Name));
    if (TheControl is TWinControl) or (TheControl is TGraphicControl) then
     begin
      if (TheControl is TEdit) or (TheControl is TBitBtn) then
       begin
        TheOwner := TheControl.Parent;
        CoordJoin.y := TheControl.Top + 1;
        CoordJoin.x := TheControl.Left + TheControl.Width + 2;
        TheJoinControl := TheOwner.ControlAtPos(CoordJoin, true, true);
        if TheJoinControl <> nil then
         begin
          if (TheJoinControl is TButton) or (TheJoinControl is TBitBtn) or (TheJoinControl is TComboBox) then
           begin
            SetLength(TabEditBtnFr, K + 1, 2);
            TabEditBtnFr[K, 0] := TheControl.Name;
            TabEditBtnFr[K, 1] := TheJoinControl.Name;
            Inc(K, 1);
           end;
         end;
       end;

      RGN := TheControl.BoundsRect;
      OK := False;
      J := 0;
      while OK = False do
       begin
        if TheControl.Parent <> nil then
         begin
          Inc(J,1);
          TheControl := TheControl.Parent;
         end
        else
         OK := True;
       end;
      if J > MaxLine then
       begin
        MaxCol := 0;
        MaxLine := J;
        SetLength(TabCoordFr, J);
        SetLength(TabCoordFr[(J - 1)], 5);
       end
      else
       begin
        MaxCol := Length(TabCoordFr[(J - 1)]);
        SetLength(TabCoordFr[(J - 1)], (MaxCol + 5));
       end;

      TabCoordFr[(J - 1), MaxCol] := BFrame.Components[I].Name;
      TabCoordFr[(J - 1), (MaxCol + 1)] := RGN.Left;
      TabCoordFr[(J - 1), (MaxCol + 2)] := RGN.Top;
      TabCoordFr[(J - 1), (MaxCol + 3)] := RGN.Right;
      TabCoordFr[(J - 1), (MaxCol + 4)] := RGN.Bottom;
     end;
   end;
end;

procedure TAutoResize.ResizeTheF(BForm : TForm);
var
 TheControl, TheJoinControl : TControl;
 I, J, L, T, R, B, W, H, NewHeight, NewWidth : Integer;
  procedure SetBounds(Control: TControl);
   begin
    Control.SetBounds(L, T, W, H);
   end;
begin
 BForm.HorzScrollBar.Position := 0;
 BForm.VertScrollBar.Position := 0;
 BForm.AutoScroll := False;
 NewHeight := BForm.ClientHeight;
 NewWidth := BForm.ClientWidth;

 if (NewHeight >= OldHeight)  and (NewWidth >= OldWidth) then
  begin
   for I := 0 to High(TabCoord) do
    begin
     J := 0;
     while J <= High(TabCoord[I]) do
      begin
       TheControl := TControl(BForm.FindComponent(TabCoord[I,J]));
       if (TheControl is TWinControl) or (TheControl is TGraphicControl) then
        begin
         if (TheControl is TPageControl) or (TheControl is TTabSheet) or
            (TheControl is TStringGrid) or (TheControl is TListBox) or
            (TheControl is TGroupBox) or (TheControl is TPanel) or (TheControl is TTreeView) or
            (TheControl is TListView) or (TheControl is TDBGrid) or (TheControl is TMemo) or
            (TheControl is TTreeView) or (TheControl.ClassParent = TFrame) then
          begin
           L := ((TabCoord[I,(J + 1)] * NewWidth) div OldWidth);
           T := ((TabCoord[I,(J + 2)] * NewHeight) div OldHeight);
           R := ((TabCoord[I,(J + 3)] * NewWidth) div OldWidth);
           B := ((TabCoord[I,(J + 4)] * NewHeight) div OldHeight);
           W := R - L;
           H := B - T;
           SetBounds(TheControl);
           Inc(J,5);
          end
         else
          begin
           L := ((TabCoord[I,(J + 1)] * NewWidth) div OldWidth);
           T := ((TabCoord[I,(J + 2)] * NewHeight) div OldHeight);
           W := TheControl.Width;
           H := TheControl.Height;
           SetBounds(TheControl);
           Inc(J,5);
          end;
        end;
      end;
    end;
    for I := 0 to high(TabEditBtn) do
     begin
      TheControl := TControl(BForm.FindComponent(TabEditBtn[I, 0]));
      TheJoinControl := TControl(BForm.FindComponent(TabEditBtn[I, 1]));
      TheJoinControl.Left := TheControl.Left + TheControl.Width + 1;
     end;
  end
 else
  begin
   for I := 0 to High(TabCoord) do
    begin
     J := 0;
     while J <= High(TabCoord[I]) do
      begin
       TheControl := TControl(BForm.FindComponent(TabCoord[I,J]));
       if (TheControl is TWinControl) or (TheControl is TGraphicControl) then
        begin
         L := (TabCoord[I,(J + 1)]);
         T := (TabCoord[I,(J + 2)]);
         R := (TabCoord[I,(J + 3)]);
         B := (TabCoord[I,(J + 4)]);
         W := R - L;
         H := B - T;
         SetBounds(TheControl);
         Inc(J,5);
        end;
      end;
    end;
      BForm.AutoScroll := True;
      BForm.HorzScrollBar.Visible := True;
      BForm.HorzScrollBar.Range := OldWidth;
      BForm.VertScrollBar.Visible := True;
      BForm.VertScrollBar.Range := OldHeight;
  end;
end;

procedure TAutoResize.ResizeTheFr(BFrame : TFrame);
var
 TheControl, TheJoinControl : TControl;
 I, J, L, T, R, B, W, H, NewHeight, NewWidth : Integer;
  procedure SetBounds(Control: TControl);
   begin
    Control.SetBounds(L, T, W, H);
   end;
begin

 NewHeight := BFrame.Height;
 NewWidth := BFrame.Width;

 if (NewHeight >= OldHeightFr)  and (NewWidth >= OldWidthFr) then
  begin
   for I := 0 to High(TabCoordFr) do
    begin
     J := 0;
     while J <= High(TabCoordFr[I]) do
      begin
       TheControl := TControl(BFrame.FindComponent(TabCoordFr[I,J]));
       if (TheControl is TWinControl) or (TheControl is TGraphicControl) then
        begin
         if (TheControl is TPageControl) or (TheControl is TTabSheet) or
            (TheControl is TStringGrid) or (TheControl is TListBox) or
            (TheControl is TGroupBox) or (TheControl is TPanel) or (TheControl is TTreeView) or
            (TheControl is TListView) or (TheControl is TDBGrid) or (TheControl is TMemo) or
            (TheControl.ClassParent = TFrame)then
          begin
           L := ((TabCoordFr[I,(J + 1)] * NewWidth) div OldWidthFr);
           T := ((TabCoordFr[I,(J + 2)] * NewHeight) div OldHeightFr);
           R := ((TabCoordFr[I,(J + 3)] * NewWidth) div OldWidthFr);
           B := ((TabCoordFr[I,(J + 4)] * NewHeight) div OldHeightFr);
           W := R - L;
           H := B - T;
           SetBounds(TheControl);
           Inc(J,5);
          end
         else
          begin
           L := ((TabCoordFr[I,(J + 1)] * NewWidth) div OldWidthFr);
           T := ((TabCoordFr[I,(J + 2)] * NewHeight) div OldHeightFr);
           W := TheControl.Width;
           H := TheControl.Height;
           SetBounds(TheControl);
           Inc(J,5);
          end;
        end;
      end;
    end;
    for I := 0 to high(TabEditBtnFr) do
     begin
      TheControl := TControl(BFrame.FindComponent(TabEditBtnFr[I, 0]));
      TheJoinControl := TControl(BFrame.FindComponent(TabEditBtnFr[I, 1]));
      TheJoinControl.Left := TheControl.Left + TheControl.Width + 1;
     end;
  end
 else
  begin
   for I := 0 to High(TabCoordFr) do
    begin
     J := 0;
     while J <= High(TabCoordFr[I]) do
      begin
       TheControl := TControl(BFrame.FindComponent(TabCoordFr[I,J]));
       if (TheControl is TWinControl) or (TheControl is TGraphicControl) then
        begin
         L := (TabCoordFr[I,(J + 1)]);
         T := (TabCoordFr[I,(J + 2)]);
         R := (TabCoordFr[I,(J + 3)]);
         B := (TabCoordFr[I,(J + 4)]);
         W := R - L;
         H := B - T;
         SetBounds(TheControl);
         Inc(J,5);
        end;
      end;
    end;
  end;
end;

end.

MyAutoResize : TAutoResize;

FrAutoResize : TAutoResize;

In the OnShow Event, we set :

procedure TForm.FormOnShow(Sender: TObject);
begin
 MyAutoResize := TAutoResize.Create(Self);
 MyAutoResize.GetFormInfo(Form);
 FFrame.GetAutoResizeFrameInfo(FFrame);
end;

procedure TForm.FormOnResize(Sender: TObject);
begin
MyAutoResize.ResizeTheF(Form);
end;

procedure TForm.FormOnClose(Sender: TObject; var Action: TCloseAction);
begin
  MyAutoResize.Free;
  FFrame.FreeAutoResize;
end;

procedure T Frame.GetAutoResizeFrameInfo(TheFrame : TFrame);
begin
 FrAutoResize := TAutoResize.Create(Self);
 FrAutoResize.GetFrameInfo(TheFrame);
end;

procedure T Frame.FrameResize(Sender: TObject);
begin
 if FrAutoResize <> nil then
   FrAutoResize.ResizeTheFr(Sender as TFrame);
end;

procedure TFrame.FreeAutoResize;
begin
 FrAutoResize.Free;
end;