private void HandleARGBScroll(object sender, ScrollEventArgs e)
{
// If the R, G, or B values change, use this
// code to update the HSV values and invalidate
// the color wheel (so it updates the pointers).
// Check the isInUpdate flag to avoid recursive events
// when you update the NumericUpdownControls.
changeType = ChangeStyle.ARGB;
ARGB = new ColorHandler.ARGB(hsbAlpha.Value, hsbRed.Value, hsbGreen.Value, hsbBlue.Value);
SetAHSV(ColorHandler.ARGBtoAHSV(ARGB));
SetARGBLabels(ARGB);
this.Invalidate();
}
private void CalcCoordsAndUpdate(ColorHandler.AHSV AHSV)
{
// Convert color to real-world coordinates and then calculate
// the various points. AHSV.Hue represents the degrees (0 to 360),
// AHSV.Saturation represents the radius.
// This procedure doesn't draw anything--it simply
// updates class-level variables. The UpdateDisplay
// procedure uses these values to update the screen.
// Given the angle (AHSV.Hue), and distance from
// the center (AHSV.Saturation), and the center,
// calculate the point corresponding to
// the selected color, on the color wheel.
colorPoint = GetPoint((double)AHSV.Hue / 255 * 360,
(double)AHSV.Saturation / 255 * radius,
centerPoint);
// Given the brightness (AHSV.value), calculate the
// point corresponding to the brightness indicator.
brightnessPoint = CalcBrightnessPoint(AHSV.Value);
// Store information about the selected color.
brightness = AHSV.Value;
selectedColor = ColorHandler.AHSVtoColor(AHSV);
ARGB = ColorHandler.AHSVtoARGB(AHSV);
// The full color is the same as AHSV, except that the
// brightness is set to full (255). This is the top-most
// color in the brightness gradient.
fullColor = ColorHandler.AHSVtoColor(AHSV.Alpha, AHSV.Hue, AHSV.Saturation, 255);
// Given the brightness (AHSV.value), calculate the
// point corresponding to the alpha indicator.
alphaPoint = CalcAlphaPoint(AHSV.Alpha);
// Store information about the selected color.
alpha = AHSV.Alpha;
}
public ColorChangedEventArgs(ColorHandler.ARGB RGB, ColorHandler.AHSV HSV)
{
mRGB = RGB;
mHSV = HSV;
}
public void Draw(Graphics g, Point mousePoint)
{
// You've moved the mouse.
// Now update the screen to match.
double distance;
int degrees;
Point delta;
Point newColorPoint;
Point newBrightnessPoint;
Point newAlphaPoint;
Point newPoint;
// Keep track of the previous color pointer point,
// so you can put the mouse there in case the
// user has clicked outside the circle.
newColorPoint = colorPoint;
newBrightnessPoint = brightnessPoint;
newAlphaPoint = alphaPoint;
// Store this away for later use.
this.g = g;
if (currentState == MouseState.MouseUp)
{
if (!mousePoint.IsEmpty)
{
if (colorRegion.IsVisible(mousePoint))
{
// Is the mouse point within the color circle?
// If so, you just clicked on the color wheel.
currentState = MouseState.ClickOnColor;
}
else if (brightnessRegion.IsVisible(mousePoint))
{
// Is the mouse point within the brightness area?
// You clicked on the brightness area.
currentState = MouseState.ClickOnBrightness;
}
else if (alphaRegion.IsVisible(mousePoint))
{
// Is the mouse point within the alpha area?
// You clicked on the alpha area.
currentState = MouseState.ClickOnAlpha;
}
else
{
// Clicked outside the color, brightness and alpha
// regions. In that case, just put the
// pointers back where they were.
currentState = MouseState.ClickOutsideRegion;
}
}
}
switch (currentState)
{
case MouseState.ClickOnBrightness:
case MouseState.DragInBrightness:
// Calculate new color information
// based on the brightness, which may have changed.
newPoint = mousePoint;
if (newPoint.Y < brightnessMin)
{
newPoint.Y = brightnessMin;
}
else if (newPoint.Y > brightnessMax)
{
newPoint.Y = brightnessMax;
}
newBrightnessPoint = new Point(brightnessX, newPoint.Y);
brightness = (int)((brightnessMax - newPoint.Y) * brightnessScaling);
AHSV.Value = brightness;
ARGB = ColorHandler.AHSVtoARGB(AHSV);
break;
case MouseState.ClickOnAlpha:
case MouseState.DragInAlpha:
// Calculate new color information
// based on the alpha, which may have changed.
newPoint = mousePoint;
if (newPoint.Y < alphaMin)
{
newPoint.Y = alphaMin;
}
else if (newPoint.Y > alphaMax)
{
newPoint.Y = alphaMax;
}
newAlphaPoint = new Point(alphaX, newPoint.Y);
alpha = (int)((alphaMax - newPoint.Y) * alphaScaling);
AHSV.Alpha = alpha;
ARGB = ColorHandler.AHSVtoARGB(AHSV);
break;
case MouseState.ClickOnColor:
case MouseState.DragInColor:
// Calculate new color information
// based on selected color, which may have changed.
newColorPoint = mousePoint;
// Calculate x and y distance from the center,
// and then calculate the angle corresponding to the
// new location.
delta = new Point(
mousePoint.X - centerPoint.X, mousePoint.Y - centerPoint.Y);
degrees = CalcDegrees(delta);
// Calculate distance from the center to the new point
// as a fraction of the radius. Use your old friend,
// the Pythagorean theorem, to calculate this value.
distance = Math.Sqrt(delta.X * delta.X + delta.Y * delta.Y) / radius;
if (currentState == MouseState.DragInColor)
{
if (distance > 1)
{
// Mouse is down, and outside the circle, but you
// were previously dragging in the color circle.
// What to do?
// In that case, move the point to the edge of the
// circle at the correct angle.
distance = 1;
newColorPoint = GetPoint(degrees, radius, centerPoint);
}
}
// Calculate the new AHSV and RGB values.
AHSV.Hue = (int)(degrees * 255 / 360);
AHSV.Saturation = (int)(distance * 255);
AHSV.Value = brightness;
ARGB = ColorHandler.AHSVtoARGB(AHSV);
fullColor = ColorHandler.AHSVtoColor(AHSV.Alpha, AHSV.Hue, AHSV.Saturation, 255);
break;
}
selectedColor = ColorHandler.AHSVtoColor(AHSV);
// Raise an event back to the parent form,
// so the form can update any UI it's using
// to display selected color values.
OnColorChanged(ARGB, AHSV);
// On the way out, set the new state.
switch (currentState)
{
case MouseState.ClickOnBrightness:
currentState = MouseState.DragInBrightness;
break;
case MouseState.ClickOnAlpha:
currentState = MouseState.DragInAlpha;
break;
case MouseState.ClickOnColor:
currentState = MouseState.DragInColor;
break;
case MouseState.ClickOutsideRegion:
currentState = MouseState.DragOutsideRegion;
break;
}
// Store away the current points for next time.
colorPoint = newColorPoint;
brightnessPoint = newBrightnessPoint;
alphaPoint = newAlphaPoint;
// Draw the gradients and points.
UpdateDisplay();
}
