The C Users' Group Library 1994 August/wc-cdrom-cusersgrouplibrary-1994-08.iso/listings/v_02_01/2n01041a

Text File | 1990-06-26 | 11KB | 431 lines

(*    Panel Unit  --  EgaVga Graphic Radio-Button Panel

        Turbo Pascal 4 Unit

        **************************************************
        NOTE:   All compilations should have the boolean
                evaluation option set to "short-circuit"
        **************************************************

    Supports MicroSoft compatible Mouse Driver

    June 26, 1990  --  Michael Kelly  --  Version 1.01      *)

Unit Panel;

InterFace
Uses PanelDrv, Graph, Int16, Mouse;

    Const
    Gap = 25;       { pixel space between buttons }
    MaxButton = 10; { maximum number of buttons on panel }

    Type
    ButtonState = (Up, Down);
    ButtonTag = String[80]; { option string }
    Button = Record         { button and associated option string }
        State          : ButtonState;
        UpperLeftX,
        UpperLeftY,
        TagColor    : Integer;
                Tag         : ButtonTag;
    End;

    Buttons    = Array[1..MaxButton] of Button;

    ButtonDescriptor = Record   { attributes common to 3D buttons }
        RadioButton    : Buttons;
                SideLength,
        BorderWidth,
        HighLightEdge,
        ShadowEdge,
        Normal,
        TagHighLight,
        TagNormal    : Integer;
    End;

    PanelDescriptor = Record    { defines a radio-button panel }
        UpperLeftX,
        UpperLeftY,
        LowerRightX,
        LowerRightY,
        NumButtons, CurrentButton    : Integer;
        ButtonStyle            : ButtonDescriptor;
    End;

(*
 *  draws the panel defined by the PanelDescriptor parameter
 *
 *  returns:
 *              True on success
 *
 *              False on error
 *)
Function DrawPanel(Var ButtonPanel : PanelDescriptor) : Boolean;

(*
 *  polling function updates button panel appearence to reflect
 *  keyboard and mouse input, and determines if a button has been
 *  pressed
 *
 *  note:   does not wait for input
 *
 *  returns:
 *              0 if no button pressed
 *
 *              user selection in range 1 to MaxButton if button pressed
 *)
Function ButtonPress(Var ButtonPanel : PanelDescriptor) : Integer;

Implementation

(*
 *  draws the button outline using highlighting and shading
 *
 *  returns:
 *              True on success
 *
 *              False on error
 *)
Function ButtonBorder(
    Var ButtonInfo : ButtonDescriptor; ThisButton : Integer) : Boolean;

    Var
    n, TopLColor, BotRColor, LSide,
    xl, xr, yu, yd : Integer;
Begin
  With ButtonInfo do
  Begin
    If RadioButton[ThisButton].State = Up then
    Begin
      TopLColor := HighlightEdge;
      BotRColor := ShadowEdge;
    End
    Else
    Begin
      TopLColor := ShadowEdge;
      BotRColor := HighLightEdge;
    End;
    LSide := SideLength;
    xl := RadioButton[ThisButton].UpperLeftX;
    xr := xl + LSide;
    yu := RadioButton[ThisButton].UpperLeftY;
    yd := yu + LSide;
    SetColor(TopLColor);
    For n := 0 to BorderWidth - 1 do
    Begin
      Line(xl+n, yd-n, xl+n, yu+n);
      Line(xl+n, yu+n, xr-n, yu+n);
    End;
    SetColor(BotRColor);
    For n := 0 to BorderWidth - 1 do
    Begin
      Line(xr-n, yu+n+1, xr-n, yd-n);
      Line(xr-n, yd-n, xl+n+1, yd-n);
    End;
  End; { With ButtonInfo }
  ButtonBorder := GraphResult = GrOk;
End;
(* ButtonBorder *)

(*
*  adjusts button state, highlighting and shading, then calls
*  ButtonBorder to make the 3D button appear to be "Up"
*
*  returns:
*              True on success
*
*              False on error
*)
Function ButtonUp(
    Var ButtonInfo : ButtonDescriptor; ThisButton : Integer) : Boolean;

Begin
  With ButtonInfo do
  Begin
    RadioButton[ThisButton].State := Up;
    ButtonUp := ButtonBorder(ButtonInfo, ThisButton);
  End; { With ButtonInfo }
End;
(* ButtonUp *)

(*
*  adjusts button state, highlighting and shading, then calls
*  ButtonBorder to make the 3D button appear to be "Down"
*
*  returns:
*              True on success
*
*              False on error
*)
Function ButtonDown(
    Var ButtonInfo : ButtonDescriptor; ThisButton : Integer) : Boolean;

Begin
  With ButtonInfo do
  Begin
    RadioButton[ThisButton].State := Down;
    ButtonDown := ButtonBorder(ButtonInfo, ThisButton);
  End; { With ButtonInfo }
End;
(* ButtonDown *)

(*
*  sets button state to "Up", then draws button and associated
*  option string (ButtonTag)
*
*  returns:
*              True on success
*
*              False on error
*)
Function DrawButton(
    Var ButtonInfo : ButtonDescriptor; ThisButton : Integer) : Boolean;

    Var
    x, y, color    : Integer;

Begin
  If not ButtonUp(ButtonInfo, ThisButton) then
  Begin
    DrawButton := False;
    exit;
  End;
  With ButtonInfo do
  Begin
    x := RadioButton[ThisButton].UpperLeftX + SideLength + Gap;
    y := RadioButton[ThisButton].UpperLeftY + SideLength shr 2;
    SetColor(RadioButton[ThisButton].TagColor);
    OutTextXY(x, y, RadioButton[ThisButton].Tag);
  End; { With ButtonInfo }
  DrawButton := GraphResult = GrOk;
End;
(* DrawButton *)

Function DrawPanel(Var ButtonPanel : PanelDescriptor) : Boolean;
    Var
    HighLight, Shadow, Normal, TextHighlight, TextNormal     : Integer;
    xl, xr, yu, yd, k    : Integer;
Begin
  If MouseVisible then
    ToggleMouseVisibility;
  With ButtonPanel do
  Begin
    HighLight := ButtonStyle.HighLightEdge;
    Shadow := ButtonStyle.ShadowEdge;
    Normal := ButtonStyle.Normal;
    TextNormal := ButtonStyle.TagNormal;
    TextHighLight := ButtonStyle.TagHighLight;
    xl := UpperLeftX;
    xr := LowerRightX;
    yu := UpperLeftY;
    yd := LowerRightY;
    SetColor(HighLight);
    For k := 0 to ButtonStyle.BorderWidth + 2 do
    Begin
      Line(xl+k, yd-k, xl+k, yu+k);
      Line(xl+k, yu+k, xr-k, yu+k);
    End;
    SetColor(Shadow);
    For k := 0 to ButtonStyle.BorderWidth + 2 do
    Begin
      Line(xr-k, yu+k+1, xr-k, yd-k);
      Line(xr-k, yd-k, xl+k+1, yd-k);
    End;
    SetFillStyle(SolidFill, Normal);
    Bar(xl+k, yu+k, xr-k, yd-k);
    For k := 1 to NumButtons do
    Begin
      If k = CurrentButton then
    ButtonStyle.RadioButton[k].TagColor := TextHighlight
      Else
    ButtonStyle.RadioButton[k].TagColor := TextNormal;
      If not DrawButton(ButtonStyle, k) then
      Begin
    DrawPanel := False;
    exit;
      End;
    End;
  End; { With ButtonPanel }
  If MouseOn then
    ToggleMouseVisibility;
  DrawPanel := True;
End;
(* DrawPanel *)

(*
*  checks mouse, if active, for "left mouse button down" state
*  and if True, checks mouse position to determine if a button
*  has been "clicked on"
*
*  returns:
*              0 if no button "clicked on"
*
*              number of button in range 1 to MaxButton "clicked on"
*)
Function ButtonClick(Var ButtonPanel : PanelDescriptor) : Integer;
    Var
    MX, MY, MouseButtonState : Word;
    wid, len, k : Integer;
    RButton : Buttons;
    ThisButton : Button;

Begin
  If not GetMousePosition(MX, MY, MouseButtonState) then
  Begin
    ButtonClick := 0;
    Exit;
  End;
  If (MouseButtonState and 1) <> 1 then
  Begin
    ButtonClick := 0;
    Exit;
  End;
  With ButtonPanel do
  Begin
    RButton := ButtonStyle.RadioButton;
    wid := ButtonStyle.BorderWidth;
    len := ButtonStyle.SideLength;
    For k := 1 to NumButtons do
    Begin
      ThisButton := RButton[k];
      With ThisButton do
      Begin
    If (MX >= (UpperLeftX - wid)) and
      (MX <= (UpperLeftX + len + wid)) and
    (MY >= (UpperLeftY - wid)) and
    (MY <= (UpperLeftY + len + wid)) then
    Begin
      ButtonClick := k;
      Exit;
    End;
      End; { With ThisButton }
    End; { For }
  End; { With ButtonPanel }
  ButtonClick := 0;
End;
(* ButtonClick *)

Function ButtonPress(Var ButtonPanel : PanelDescriptor) : Integer;
    Var
    KeyCode, ScanCode    : Byte;
    KeyState, Result, Done    : Boolean;
    HiLite, Norm, k, choice    : Integer;
    OldButton, ClickedOn    : Integer;

Begin
  KeyCode := 0;
  ScanCode := 0;
  ClickedOn := 0;
  Result := False;
  Done := False;
  choice := 0;
  KeyState := key_ready(KeyCode, ScanCode);
  If KeyState then
    get_key(KeyCode, ScanCode);
  If (not KeyState) and (MouseOn) then
  Begin
    ClickedOn := ButtonClick(ButtonPanel);
    If (ClickedOn <> 0) and (ClickedOn <= ButtonPanel.NumButtons) then
    Begin
      KeyState := True;
      If ClickedOn = ButtonPanel.CurrentButton then
    KeyCode := CReturn
      Else If ClickedOn = (ButtonPanel.CurrentButton - 1) then
    ScanCode := UpKey
      Else If ClickedOn = (ButtonPanel.CurrentButton + 1) then
    ScanCode := DownKey
      Else
      Begin
    With ButtonPanel do
    Begin
      Norm := ButtonStyle.TagNormal;
      HiLite := ButtonStyle.TagHighLight;
      OldButton := CurrentButton;
      CurrentButton := ClickedOn;
      ButtonStyle.RadioButton[OldButton].TagColor := Norm;
      ButtonStyle.RadioButton[CurrentButton].TagColor := HiLite;
      If MouseVisible then
        ToggleMouseVisibility;
      Result := DrawButton(ButtonStyle, OldButton);
      Result := DrawButton(ButtonStyle, CurrentButton);
      If not MouseVisible then
        ToggleMouseVisibility;
      KeyState := False;
      Done := True;
    End;  { With ButtonPanel }
      End;  { Else }
    End;  { If ClickedOn }
  End;  { If MouseOn }
  If KeyState then
  Begin
    If (MouseOn) and (MouseVisible) then
      ToggleMouseVisibility;
    With ButtonPanel do
    Begin
      HiLite := ButtonStyle.TagHighLight;
      Norm := ButtonStyle.TagNormal;
      Result := False;
      Done := False;
      If KeyCode = 0 then
      Case ScanCode of
    DownKey, UpKey:
    Begin
      OldButton := CurrentButton;
      If ScanCode = DownKey then
      Begin
        If CurrentButton < NumButtons then
          inc(CurrentButton)
        Else
          CurrentButton := 1;
      End;
      If ScanCode = UpKey then
      Begin
        If CurrentButton > 1 then
          dec(CurrentButton)
        Else
          CurrentButton := NumButtons;
      End;
      ButtonStyle.RadioButton[OldButton].TagColor := Norm;
      ButtonStyle.RadioButton[CurrentButton].TagColor := HiLite;
      Result := DrawButton(ButtonStyle, OldButton);
      Result := DrawButton(ButtonStyle, CurrentButton);
      Done := True;
    End;
    HomeKey, EndKey:
    Begin
      OldButton := CurrentButton;
      If ScanCode = EndKey then
        CurrentButton := NumButtons
      Else
        CurrentButton := 1;
      If OldButton <> CurrentButton then
      Begin
        ButtonStyle.RadioButton[OldButton].TagColor := Norm;
        ButtonStyle.RadioButton[CurrentButton].TagColor := HiLite;
        Result := DrawButton(ButtonStyle, OldButton);
        Result := DrawButton(ButtonStyle, CurrentButton);
        Done := True;
      End;
    End;
      End; { Case }
      If KeyCode <> 0 then
      Case KeyCode of
    CReturn :
    Begin
      Result := ButtonDown(ButtonStyle, CurrentButton);
      choice := CurrentButton;
      Done := True;
    End;
      End;  { Case }
    End;  { With ButtonPanel }
  End;  { If KeyState }
  If (MouseOn) and (not MouseVisible) then
    ToggleMouseVisibility;
  ButtonPress := choice;
End;
(* ButtonPress *)

End.