Category : Files from Magazines
Archive   : MAR93.ZIP
Filename : CPROG.ASC

_C PROGRAMMING COLUMN_
by Al Stevens

[LISTING ONE]

// -------- listbox.h

#ifndef LISTBOX_H
#define LISTBOX_H

#include "textbox.h"

const int LISTSELECTOR = 4; // selected list box entry
class ListBox : public TextBox {
Bool addmode; // adding extended selections mode
int anchorpoint; // anchor point for extended selections
int selectcount; // count of selected items
virtual void SetColors();
protected:
int selection; // current selection
virtual void ClearSelection();
public:
ListBox(char *ttl, int lf, int tp, int ht, int wd,
DFWindow *par) : TextBox(ttl, lf, tp, ht, wd, par)
{ OpenWindow(); }
ListBox(char *ttl, int ht, int wd, DFWindow *par)
: TextBox(ttl, ht, wd, par)
{ OpenWindow(); }
ListBox(int lf, int tp, int ht, int wd, DFWindow *par)
: TextBox(lf, tp, ht, wd, par)
{ OpenWindow(); }
ListBox(int ht, int wd, DFWindow *par) : TextBox(ht,wd,par)
{ OpenWindow(); }
ListBox(char *ttl) : TextBox(ttl)
{ OpenWindow(); }
virtual ~ListBox()
{ if (windowstate != CLOSED) CloseWindow(); }
// -------- listbox API messages
virtual void OpenWindow();
virtual void CloseWindow();
virtual void Paint();
virtual void Keyboard(int key);
virtual void SetSelection(int sel);
virtual void ButtonReleased(int mx, int my);
virtual void LeftButton(int mx, int my);
virtual void DoubleClick(int mx, int my);
virtual void Choose();
virtual void ScrollUp();
virtual void ScrollDown();
virtual void ScrollRight();
virtual void ScrollLeft();
virtual void PageUp();
virtual void PageDown();
virtual void PageRight();
virtual void PageLeft();
};
#endif




[LISTING TWO]

// ------------ listbox.cpp
#include "listbox.h"
#include "keyboard.h"

// ----------- common constructor code
void ListBox::OpenWindow()
{
windowtype = ListboxWindow;
if (windowstate == CLOSED)
TextBox::OpenWindow();
selection = -1;
addmode = False;
anchorpoint = -1;
selectcount = 0;
SetColors();
}
// -------- set the fg/bg colors for the window
void ListBox::SetColors()
{
colors.fg = YELLOW;
colors.bg = BLUE;
colors.sfg = LIGHTGRAY;
colors.sbg = BLACK;
colors.ffg = LIGHTGRAY;
colors.fbg = BLUE;
colors.hfg = BLACK;
colors.hbg = LIGHTGRAY;
}
void ListBox::CloseWindow()
{
TextBox::CloseWindow();
}
void ListBox::ClearSelection()
{
if (selection != -1)
WriteTextLine(selection, colors.fg, colors.bg);
}
void ListBox::SetSelection(int sel)
{
ClearSelection();
if (sel >= 0 && sel < wlines) {
selection = sel;
WriteTextLine(sel, colors.sfg, colors.sbg);
}
}
void ListBox::Keyboard(int key)
{
int sel = selection; // (ClearSelection changes selection)
switch (key) {
case UP:
if (sel > 0) {
ClearSelection();
if (sel == wtop)
ScrollDown();
SetSelection(sel-1);
}
return;
case DN:
if (sel < wlines-1) {
ClearSelection();
if (sel == wtop+ClientHeight()-1)
ScrollUp();
SetSelection(sel+1);
}
return;
case '\r':
Choose();
return;
default:
break;
}
TextBox::Keyboard(key);
}
// ---------- paint the listbox
void ListBox::Paint()
{
TextBox::Paint();
if (text != NULL)
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::ScrollUp()
{
TextBox::ScrollUp();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::ScrollDown()
{
TextBox::ScrollDown();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::ScrollRight()
{
TextBox::ScrollRight();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::ScrollLeft()
{
TextBox::ScrollLeft();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::PageUp()
{
TextBox::PageUp();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::PageDown()
{
TextBox::PageDown();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::PageRight()
{
TextBox::PageRight();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
void ListBox::PageLeft()
{
TextBox::PageLeft();
WriteTextLine(selection, colors.sfg, colors.sbg);
}
// ---------- Left mouse button was clicked
void ListBox::LeftButton(int mx, int my)
{
if (my != prevmouseline) {
if (ClientRect().Inside(mx, my)) {
int y = my - ClientTop();
if (wlines && y < wlines-wtop)
SetSelection(wtop+y);
}
}
DFWindow::LeftButton(mx, my);
}
void ListBox::DoubleClick(int mx, int my)
{
if (ClientRect().Inside(mx, my)) {
my -= ClientTop();
if (wlines && my < wlines-wtop)
Choose();
}
DFWindow::DoubleClick(mx, my);
}
void ListBox::ButtonReleased(int, int)
{
prevmouseline = -1;
}
void ListBox::Choose()
{
// --- does nothing yet
}



[LISTING THREE]


// ----------- pbutton.h
#ifndef PBUTTON_H
#define PBUTTON_H

#include "textbox.h"
class PushButton : public TextBox {
virtual void SetColors();
Bool pressed;
DFWindow *owner; // window that gets the command
void (DFWindow::*cmdfunction)(); // selection function
public:
PushButton(char *lbl, int lf, int tp, DFWindow *par);
virtual ~PushButton()
{ if (windowstate != CLOSED) CloseWindow(); }
// -------- API messages
virtual void OpenWindow();
virtual void CloseWindow();
virtual Bool SetFocus();
virtual void ResetFocus();
virtual void Paint();
virtual void Shadow();
virtual void Keyboard(int key);
virtual void LeftButton(int mx, int my);
virtual void ButtonReleased(int mx, int my);
virtual void MouseMoved(int mx, int my);
virtual void KeyReleased();
virtual void PressButton();
virtual void ReleaseButton();
virtual void ButtonCommand();
void SetButtonFunction(DFWindow *wnd,
void (DFWindow::*cmdfunc)())
{ owner = wnd; cmdfunction = cmdfunc; }
};
#endif


[LISTING FOUR]

// ------------- pbutton.cpp
#include "pbutton.h"
#include "desktop.h"

PushButton::PushButton(char *lbl, int lf, int tp, DFWindow *par)
: TextBox(lf, tp, 1, strlen(lbl)+2, par)
{
OpenWindow();
String lb(" ");
lb += lbl;
lb += " ";
SetText(lb);
}
// ----------- common constructor code
void PushButton::OpenWindow()
{
windowtype = PushButtonWindow;
if (windowstate == CLOSED)
TextBox::OpenWindow();
SetColors();
pressed = False;
cmdfunction = NULL;
}
void PushButton::CloseWindow()
{
TextBox::CloseWindow();
}
// -------- set the fg/bg colors for the window
void PushButton::SetColors()
{
colors.fg = BLACK;
colors.bg = CYAN;
colors.sfg = WHITE;
colors.sbg = CYAN;
colors.ffg = BLACK;
colors.fbg = CYAN;
colors.hfg = DARKGRAY; // Inactive FG
colors.hbg = CYAN; // Inactive BG
shortcutfg = RED;
}
void PushButton::Paint()
{
if (visible) {
COLORS fg;
COLORS bg;
if (!pressed) {
if (isEnabled()) {
if (this == desktop.InFocus())
fg = colors.sfg;
else
fg = colors.fg;
WriteShortcutLine(0, fg, colors.bg);
}
else
WriteTextLine(0, colors.hfg, colors.hbg);
}
else {
// ---- display a pressed button
fg = ClientBG();
bg = Parent()->ClientBG();
int wd = Width();
WriteWindowChar(' ', 0, 0, fg, bg);
for (int x = 0; x < wd; x++) {
WriteWindowChar(220, x+1, 0, fg, bg);
WriteWindowChar(223, x+1, 1, fg, bg);
}
}
}
}
void PushButton::Shadow()
{
if (visible && (attrib & SHADOW)) {
COLORS bg = Parent()->ClientBG();
int wd = Width();
WriteWindowChar(220, wd, 0, BLACK, bg);
for (int x = 1; x <= wd; x++)
WriteWindowChar(223, x, 1, BLACK, bg);
}
}
Bool PushButton::SetFocus()
{
TextBox::SetFocus();
Paint();
return True;
}
void PushButton::ResetFocus()
{
TextBox::ResetFocus();
Paint();
}
void PushButton::Keyboard(int key)
{
if (key == '\r')
PressButton();
else
TextBox::Keyboard(key);
}
void PushButton::LeftButton(int mx, int my)
{
if (ClientRect().Inside(mx,my)) {
PressButton();
CaptureFocus();
}
}
void PushButton::MouseMoved(int mx, int my)
{
if (desktop.FocusCapture() == this)
if (ClientRect().Inside(mx,my))
PressButton();
else
ReleaseButton();
}
void PushButton::ButtonReleased(int, int)
{
ReleaseFocus();
ButtonCommand();
}
void PushButton::KeyReleased()
{
ButtonCommand();
}
void PushButton::ButtonCommand()
{
if (pressed) {
ReleaseButton();
if (cmdfunction != NULL && owner != NULL)
(owner->*cmdfunction)();
}
}
void PushButton::PressButton()
{
if (!pressed) {
pressed = True;
Paint();
}
}
void PushButton::ReleaseButton()
{
if (pressed) {
pressed = False;
Paint();
Shadow();
}
}



[LISTING FIVE]

// ----------- button.h
#ifndef BUTTON_H
#define BUTTON_H

#include "textbox.h"
class Button : public TextBox {
virtual void SetColors();
Bool setting;
protected:
char setchar;
Button(char *lbl, int lf, int tp, DFWindow *par);
virtual ~Button()
{ if (windowstate != CLOSED) CloseWindow(); }
public:
// -------- API messages
virtual void OpenWindow();
virtual void CloseWindow();
virtual Bool SetFocus();
virtual void ResetFocus();
virtual void Paint();
virtual void Keyboard(int key);
virtual void LeftButton(int mx, int my);
virtual void InvertButton();
virtual void PushButton();
virtual void ReleaseButton();
Bool Setting() { return setting; }
};
#endif

[LISTING SIX]

// ------------- button.cpp
#include "button.h"
#include "desktop.h"
Button::Button(char *lbl, int lf, int tp, DFWindow *par)
: TextBox(lf, tp, 1, strlen(lbl)+5, par)
{
OpenWindow();
String lb("( ) ");
lb += lbl;
lb += " ";
SetText(lb);
}
// ----------- common constructor code
void Button::OpenWindow()
{
if (windowstate == CLOSED)
TextBox::OpenWindow();
SetColors();
setting = False;
setchar = ' ';
}
void Button::CloseWindow()
{
TextBox::CloseWindow();
}
// -------- set the fg/bg colors for the window
void Button::SetColors()
{
colors.fg =
colors.sfg =
colors.ffg =
colors.hfg = Parent()->ClientFG();
colors.bg =
colors.sbg =
colors.fbg =
colors.hbg = Parent()->ClientBG();
shortcutfg = RED;
}
void Button::Paint()
{
if (visible) {
(*text)[1] = setting ? setchar : ' ';
if (isEnabled())
WriteShortcutLine(0, colors.fg, colors.bg);
else
WriteTextLine(0, colors.hfg, colors.hbg);
}
}
Bool Button::SetFocus()
{
TextBox::SetFocus();
desktop.cursor().normalcursor();
desktop.cursor().SetPosition(Left()+1, Top());
desktop.cursor().Show();
return True;
}
void Button::ResetFocus()
{
TextBox::ResetFocus();
desktop.cursor().Hide();
}
void Button::Keyboard(int key)
{
if (key == ' ')
InvertButton();
else
TextBox::Keyboard(key);
}
void Button::LeftButton(int mx, int my)
{
if (ClientRect().Inside(mx,my))
InvertButton();
}
void Button::InvertButton()
{
if (setting)
ReleaseButton();
else
PushButton();
}
void Button::PushButton()
{
setting = True;
Paint();
}
void Button::ReleaseButton()
{
setting = False;
Paint();
}

[LISTING SEVEN]

// ----------- radio.h
#ifndef RADIO_H
#define RADIO_H

#include "button.h"
class RadioButton : public Button {
public:
RadioButton(char *lbl, int lf, int tp, DFWindow *par);
virtual ~RadioButton()
{ if (windowstate != CLOSED) CloseWindow(); }
// -------- API messages
virtual void InvertButton();
virtual void PushButton();
virtual void OpenWindow();
};
#endif


[LISTING EIGHT]

// ------------- radio.cpp
#include "radio.h"
#include "desktop.h"

RadioButton::RadioButton(char *lbl, int lf, int tp,
DFWindow *par) : Button(lbl, lf, tp, par)
{
OpenWindow();

setchar = 7;
}
void RadioButton::OpenWindow()
{
if (windowstate == CLOSED)
Button::OpenWindow();
windowtype = RadioButtonWindow;
}
void RadioButton::InvertButton()
{
PushButton();
}
void RadioButton::PushButton()
{
int ht = desktop.screen().Height();
DFWindow **rd = new DFWindow *[ht];
for (int i = 0; i < ht; i++)
rd[i] = NULL;
// - build a table of radio buttons at the same x coordiate
DFWindow *sib = Parent()->First();
while (sib != NULL) {
if (sib->WindowType() == RadioButtonWindow) {
if (sib->Left() == Left()) {
int tp = sib->Top();
if (tp < ht)
rd[tp] = sib;
}
}
sib = sib->Next();
}
// ----- find the start of the radiobutton group
i = Top();
while (i >= 0 && rd[i] != NULL)
--i;
// ---- ignore everthing before the group
while (i >= 0)
rd[i--] = NULL;
// ----- find the end of the radiobutton group
i = Top();
while (i < ht && rd[i] != NULL)
i++;
// ---- ignore everthing past the group
while (i < ht)
rd[i++] = NULL;
// ------ release all the radio buttons in the group
for (i = 0; i < ht; i++)
if (rd[i] != NULL)
((RadioButton *)rd[i])->ReleaseButton();
delete [] rd;
// ----- set the chosen radio button
Button::PushButton();
}

[LISTING NINE]

// ----------- checkbox.h
#ifndef CHECKBOX_H
#define CHECKBOX_H

#include "button.h"
class CheckBox : public Button {
public:
CheckBox(char *lbl, int lf, int tp, DFWindow *par);
virtual ~CheckBox()
{ if (windowstate != CLOSED) CloseWindow(); }
// -------- API messages
virtual void OpenWindow();
};
#endif



[LISTING TEN]

// ------------- checkbox.cpp
#include "checkbox.h"
#include "desktop.h"
CheckBox::CheckBox(char *lbl, int lf, int tp, DFWindow *par) :
Button(lbl, lf, tp, par)
{
OpenWindow();
setchar = 'X';
(*text)[0] = '[';
(*text)[2] = ']';
}
// ----------- common constructor code
void CheckBox::OpenWindow()
{
if (windowstate == CLOSED)
Button::OpenWindow();
windowtype = CheckBoxWindow;
}