static void TXT_ScrollPaneDrawer(TXT_UNCAST_ARG(scrollpane), int selected)
{
TXT_CAST_ARG(txt_scrollpane_t, scrollpane);
int x1, y1, x2, y2;
int scrollbars;
// We set a clipping area of the scroll pane.
x1 = scrollpane->widget.x,
y1 = scrollpane->widget.y,
x2 = x1 + scrollpane->w,
y2 = y1 + scrollpane->h;
scrollbars = NeedsScrollbars(scrollpane);
if (scrollbars & SCROLLBAR_HORIZONTAL)
{
TXT_DrawHorizScrollbar(x1,
y1 + scrollpane->h,
scrollpane->w,
scrollpane->x,
FullWidth(scrollpane) - scrollpane->w);
}
if (scrollbars & SCROLLBAR_VERTICAL)
{
TXT_DrawVertScrollbar(x1 + scrollpane->w,
y1,
scrollpane->h,
scrollpane->y,
FullHeight(scrollpane) - scrollpane->h);
}
TXT_PushClipArea(x1, x2, y1, y2);
// Draw the child widget
if (scrollpane->child != NULL)
{
TXT_DrawWidget(scrollpane->child, selected);
}
// Restore old clipping area.
TXT_PopClipArea();
}
static int NeedsScrollbars(txt_scrollpane_t *scrollpane)
{
int result;
result = 0;
if (FullWidth(scrollpane) > scrollpane->w)
{
result |= SCROLLBAR_HORIZONTAL;
}
if (FullHeight(scrollpane) > scrollpane->h)
{
result |= SCROLLBAR_VERTICAL;
}
return result;
}
static void SanityCheckScrollbars(txt_scrollpane_t *scrollpane)
{
int scrollbars;
int max_x, max_y;
scrollbars = NeedsScrollbars(scrollpane);
if ((scrollbars & SCROLLBAR_HORIZONTAL) == 0)
{
scrollpane->x = 0;
}
if ((scrollbars & SCROLLBAR_VERTICAL) == 0)
{
scrollpane->y = 0;
}
max_x = FullWidth(scrollpane) - scrollpane->w;
max_y = FullHeight(scrollpane) - scrollpane->h;
if (scrollpane->x < 0)
{
scrollpane->x = 0;
}
else if (scrollpane->x > max_x)
{
scrollpane->x = max_x;
}
if (scrollpane->y < 0)
{
scrollpane->y = 0;
}
else if (scrollpane->y > max_y)
{
scrollpane->y = max_y;
}
}
static void TXT_ScrollPaneMousePress(TXT_UNCAST_ARG(scrollpane),
int x, int y, int b)
{
TXT_CAST_ARG(txt_scrollpane_t, scrollpane);
int scrollbars;
int rel_x, rel_y;
scrollbars = NeedsScrollbars(scrollpane);
if (b == TXT_MOUSE_SCROLLUP)
{
if (scrollbars & SCROLLBAR_VERTICAL)
{
scrollpane->y -= 3;
}
else if (scrollbars & SCROLLBAR_HORIZONTAL)
{
scrollpane->x -= 3;
}
return;
}
else if (b == TXT_MOUSE_SCROLLDOWN)
{
if (scrollbars & SCROLLBAR_VERTICAL)
{
scrollpane->y += 3;
}
else if (scrollbars & SCROLLBAR_HORIZONTAL)
{
scrollpane->x += 3;
}
return;
}
rel_x = x - scrollpane->widget.x;
rel_y = y - scrollpane->widget.y;
// Click on the horizontal scrollbar?
if ((scrollbars & SCROLLBAR_HORIZONTAL) && rel_y == scrollpane->h)
{
if (rel_x == 0)
{
--scrollpane->x;
}
else if (rel_x == scrollpane->w - 1)
{
++scrollpane->x;
}
else
{
int range = FullWidth(scrollpane) - scrollpane->w;
int bar_max = scrollpane->w - 3;
scrollpane->x = ((rel_x - 1) * range + bar_max - 1) / bar_max;
}
return;
}
// Click on the vertical scrollbar?
if ((scrollbars & SCROLLBAR_VERTICAL) && rel_x == scrollpane->w)
{
if (rel_y == 0)
{
--scrollpane->y;
}
else if (rel_y == scrollpane->h - 1)
{
++scrollpane->y;
}
else
{
int range = FullHeight(scrollpane) - scrollpane->h;
int bar_max = scrollpane->h - 3;
scrollpane->y = ((rel_y - 1) * range + bar_max - 1) / bar_max;
}
return;
}
if (scrollpane->child != NULL)
{
TXT_WidgetMousePress(scrollpane->child, x, y, b);
}
}
static int InterpretScrollKey(txt_scrollpane_t *scrollpane, int key)
{
int maxy;
switch (key)
{
case KEY_UPARROW:
if (scrollpane->y > 0)
{
--scrollpane->y;
return 1;
}
break;
case KEY_DOWNARROW:
if (scrollpane->y < FullHeight(scrollpane) - scrollpane->h)
{
++scrollpane->y;
return 1;
}
break;
case KEY_LEFTARROW:
if (scrollpane->x > 0)
{
--scrollpane->x;
return 1;
}
break;
case KEY_RIGHTARROW:
if (scrollpane->x < FullWidth(scrollpane) - scrollpane->w)
{
++scrollpane->x;
return 1;
}
break;
case KEY_PGUP:
if (scrollpane->y > 0)
{
scrollpane->y -= scrollpane->h;
if (scrollpane->y < 0)
{
scrollpane->y = 0;
}
return 1;
}
break;
case KEY_PGDN:
maxy = FullHeight(scrollpane) - scrollpane->h;
if (scrollpane->y < maxy)
{
scrollpane->y += scrollpane->h;
if (scrollpane->y > maxy)
{
scrollpane->y = maxy;
}
return 1;
}
break;
default:
break;
}
return 0;
}