/// <summary>
/// <para>Constructs a new <see cref="T:Xsharp.Graphics"/> object and
/// attaches it to a <see cref="T:Xsharp.Drawable"/> instance.</para>
/// </summary>
///
/// <param name="drawable">
/// <para>The drawable to attach this graphics context to. If the
/// drawable is a widget, the foreground and background colors of the
/// graphics object will be initially set to the widget's standard
/// foreground and background colors.</para>
/// </param>
///
/// <exception cref="T:System.ArgumentNullException">
/// <para>Raised if <paramref name="drawable"/> is <see langword="null"/>.
/// </para>
/// </exception>
///
/// <exception cref="T:Xsharp.XInvalidOperationException">
/// <para>Raised if <paramref name="drawable"/> does not support
/// output, is disposed, or is the root window.</para>
/// </exception>
public Graphics(Drawable drawable)
{
if(drawable == null)
{
throw new ArgumentNullException("drawable");
}
else if(drawable.Kind == DrawableKind.InputOnlyWidget)
{
throw new XInvalidOperationException
(S._("X_GraphicsIsOutputOnly"));
}
else if(drawable is RootWindow)
{
throw new XInvalidOperationException
(S._("X_NonRootOperation"));
}
dpy = drawable.dpy;
this.drawable = drawable;
XGCValues gcValues = new XGCValues();
InputOutputWidget widget = (drawable as InputOutputWidget);
DoubleBuffer buffer = (drawable as DoubleBuffer);
Bitmap bitmap = (drawable as Bitmap);
if(widget != null)
{
foreground = widget.Foreground;
background = widget.Background;
}
else if(buffer != null)
{
foreground = buffer.Widget.Foreground;
background = buffer.Widget.Background;
}
else if(bitmap != null)
{
foreground = new Color(0x00, 0x00, 0x00);
background = new Color(0xFF, 0xFF, 0xFF);
}
else
{
foreground = new Color (StandardColor.Foreground);
background = new Color (StandardColor.Background);
}
gcValues.foreground = drawable.ToPixel(foreground);
gcValues.background = drawable.ToPixel(background);
if(drawable is DoubleBuffer)
{
((DoubleBuffer)drawable).Start(this);
}
try
{
IntPtr display = dpy.Lock();
drawableHandle = drawable.GetGCHandle();
gc = drawable.screen.GetGC(bitmap != null);
if(gc == IntPtr.Zero)
{
// Create a new GC because the cache is empty.
gc = Xlib.XCreateGC(display, drawableHandle,
(uint)(GCValueMask.GCForeground |
GCValueMask.GCBackground),
ref gcValues);
if(gc == IntPtr.Zero)
{
Display.OutOfMemory();
}
}
else
{
// Reset the cached GC back to the default settings.
// Xlib will take care of stripping the list down
// to just the changes that need to be applied.
gcValues.function = Xsharp.GCFunction.GXcopy;
gcValues.plane_mask = ~((XPixel)0);
gcValues.line_width = 0;
gcValues.line_style = Xsharp.LineStyle.LineSolid;
gcValues.cap_style = Xsharp.CapStyle.CapButt;
gcValues.join_style = Xsharp.JoinStyle.JoinMiter;
gcValues.fill_style = Xsharp.FillStyle.FillSolid;
gcValues.fill_rule = Xsharp.FillRule.EvenOddRule;
gcValues.arc_mode = Xsharp.ArcMode.ArcPieSlice;
gcValues.ts_x_origin = 0;
gcValues.ts_y_origin = 0;
gcValues.subwindow_mode =
Xsharp.SubwindowMode.ClipByChildren;
gcValues.graphics_exposures = true;
gcValues.clip_x_origin = 0;
gcValues.clip_y_origin = 0;
gcValues.clip_mask = XPixmap.Zero;
gcValues.dash_offset = 0;
gcValues.dashes = (sbyte)4;
Xlib.XChangeGC(display, gc,
(uint)(GCValueMask.GCFunction |
GCValueMask.GCPlaneMask |
GCValueMask.GCForeground |
GCValueMask.GCBackground |
GCValueMask.GCLineWidth |
GCValueMask.GCLineStyle |
GCValueMask.GCCapStyle |
GCValueMask.GCJoinStyle |
GCValueMask.GCFillStyle |
GCValueMask.GCFillRule |
GCValueMask.GCTileStipXOrigin |
GCValueMask.GCTileStipYOrigin |
GCValueMask.GCSubwindowMode |
GCValueMask.GCGraphicsExposures |
GCValueMask.GCClipXOrigin |
GCValueMask.GCClipYOrigin |
GCValueMask.GCClipMask |
GCValueMask.GCDashOffset |
GCValueMask.GCDashList |
GCValueMask.GCArcMode),
ref gcValues);
}
int sn = drawable.screen.ScreenNumber;
double px, mm;
px = (double)Xlib.XDisplayWidth(display, sn);
mm = (double)Xlib.XDisplayWidthMM(display, sn);
dpiX = (float)((px * 25.4) / mm);
px = (double)Xlib.XDisplayHeight(display, sn);
mm = (double)Xlib.XDisplayHeightMM(display, sn);
dpiY = (float)((px * 25.4) / mm);
}
finally
{
dpy.Unlock();
}
if(drawable is DoubleBuffer)
{
((DoubleBuffer)drawable).ClearAtStart(this);
}
isDisposed = false;
}
