//
// Set the range of the meter and updates the display.
//
void CMeterCtrl::SetRange(int range1, int range2, BOOL range_auto)
{
auto_range = range_auto;
// Disallow setting the ranges to the same value.
if (range1 == range2)
return;
min_range = ((range1 < range2) ? range1 : range2);
max_range = ((range1 > range2) ? range1 : range2);
// Make sure that the needle value is within the new range and update
// the actual angle that the needle should be.
if (value < min_range)
actual_angle = 0;
else if (value > max_range)
actual_angle = NEEDLE_SWEEP;
else
actual_angle = (int)(value / (max_range - min_range) * NEEDLE_SWEEP);
// Update the displayed scale and marker labels.
UpdateScaleInfo();
UpdateLabelInfo();
RedrawWindow();
}
//
// Handles WM_CREATE message (Window is being created)
//
int CMeterCtrl::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
CRect control_box;
POINT temp_point;
// Allow the framework to create the window
VERIFY(CWnd::OnCreate(lpCreateStruct) == 0);
// Store the control's client area rectangle
GetClientRect(&control_box);
// Determine where the pivot point should be located.
// Get the length of the longest radius that will fit inside the box.
outer_radius = (int)min(control_box.Width() / 2, control_box.Height()
/ (1 + cos(PIVOT_ARC_ANGLE * PI / 180)));
inner_radius = (int)(outer_radius * .70);
pivot_point.x = (int)(control_box.Width() / 2);
pivot_point.y = outer_radius;
// Set the size of the rectangle containing the dial.
meter_box.left = pivot_point.x - outer_radius;
meter_box.top = pivot_point.y - outer_radius;
meter_box.right = pivot_point.x + outer_radius;
meter_box.bottom = pivot_point.y + outer_radius;
// Initialize the needle's center pivot circle.
pivot_radius = inner_radius / 12;
needle_pivot.SetRect(pivot_point.x - pivot_radius,
pivot_point.y - pivot_radius, pivot_point.x + pivot_radius, pivot_point.y + pivot_radius);
// Set the points for the bounding pie wedge.
CalculatePoint(0, inner_radius, &(min_point.x), &(min_point.y));
max_point.x = pivot_point.x + (pivot_point.x - min_point.x);
max_point.y = min_point.y;
// Now set the needle to the resting position.
shown_angle = 0;
actual_angle = 0;
SetNeedlePoints();
// Create the text box for the scale display.
CalculatePoint(0, inner_radius, &scale_box.right, &temp_point.y);
CalculatePoint(0, outer_radius, &temp_point.x, &scale_box.bottom);
CalculatePoint(NEEDLE_SWEEP, inner_radius, &scale_box.left, &scale_box.top);
// Initialize information needed to display the scale and labels.
scale_font.CreateFont((int)(outer_radius * .2), 0, 0, 0, FW_NORMAL, FALSE,
FALSE, FALSE, ANSI_CHARSET, OUT_TT_PRECIS, CLIP_DEFAULT_PRECIS,
DEFAULT_QUALITY, DEFAULT_PITCH, "Arial");
label_font.CreateFont((int)(outer_radius * .18), 0, 0, 0, FW_NORMAL, FALSE,
FALSE, FALSE, ANSI_CHARSET, OUT_TT_PRECIS, CLIP_DEFAULT_PRECIS,
DEFAULT_QUALITY, DEFAULT_PITCH, "Arial");
marker_pen.CreatePen(PS_SOLID, 2, 0x00FFFFFF);
label_box_size = (int)(outer_radius * .1);
label_radius = (int)(outer_radius * .8275);
tick_mark_radius = (int)(outer_radius * .96);
UpdateScaleInfo();
UpdateLabelInfo();
// Set the points for the rectangle surrounding the watermark arc.
watermark_box.left = pivot_point.x - inner_radius - 2;
watermark_box.top = pivot_point.y - inner_radius - 2;
watermark_box.right = pivot_point.x + inner_radius + 2;
watermark_box.bottom = pivot_point.y + inner_radius + 2;
return 0;
}