What property defines a controls paint bounds?

[Tom P.]

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
.... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
.... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);

But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);

What am I really supposed to use? How do I get that last pixel
correct?

Tom P.

[Matt]

Re: What property defines a controls paint bounds?

On Feb 27, 2:20 pm, "Tom P." <padilla.he...@ gmail.comwrote:

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);
>
But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);
>
What am I really supposed to use? How do I get that last pixel
correct?
>
Tom P.

What is wrong with e.Graphics.Fill Rectangle( Brushes.White,
e.ClipRectangle );

?
Matt

[Peter Duniho]

Re: What property defines a controls paint bounds?

On Wed, 27 Feb 2008 13:20:02 -0800, Tom P. <padilla.henry@ gmail.comwrote:

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);
>
But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);
>
What am I really supposed to use? How do I get that last pixel
correct?

Just what you're doing. Either DisplayRectangl e or ClientRectangle are
appropriate, depending on your specific need (by default, they are the
same). And you need to subtract one from the width and height to get the
whole rectangle to draw.

This may seem arbitrary, but there's actually a good reason for it.
Graphical coordinates are treated as being the intersection of 0-width
lines in a grid. The pixels are _between_ these lines. A line drawn from
(0,0) to (0,100) for example will fill all of the pixels just to the right
of that 0-width vertical line between those coordinates, inclusive.

When you try to draw a rectangle a specific width and height, all of the
pixels are being drawn to the right and below of any coordinate that
describes the rectangle. This means that on the right and bottom of the
rectangle, if you've specified coordinates that are actually the absolute
outer bounds of the area in which the control can draw, those pixels fall
outside of the control and aren't drawn.

The fix is to reduce the width and height of the rectangle you're trying
to draw by the width of one pixel, so that the pixels drawn for that
rectangle fall within the control's drawable area.

Pete

[=?Utf-8?B?RmFtaWx5IFRyZWUgTWlrZQ==?=]

RE: What property defines a controls paint bounds?



"Tom P." wrote:

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
.... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
.... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);
>
But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);
>
What am I really supposed to use? How do I get that last pixel
correct?
>
Tom P.
>

It looks like you really could do it with e.Graphics.Clea r(Color.White);

[Tom P.]

Re: What property defines a controls paint bounds?

On Feb 27, 6:58 pm, Family Tree Mike
<FamilyTreeM... @discussions.mi crosoft.comwrot e:

"Tom P." wrote:

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
.... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
.... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);

>

But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);

>

What am I really supposed to use? How do I get that last pixel
correct?

>

Tom P.

>
It looks like you really could do it with e.Graphics.Clea r(Color.White);

That's fine for clearing the control to white but what would I use to
draw the black outline?

Tom P.

[Tom P.]

Re: What property defines a controls paint bounds?

On Feb 27, 5:10 pm, Matt <matttel...@spr ynet.comwrote:

On Feb 27, 2:20 pm, "Tom P." <padilla.he...@ gmail.comwrote:
>
>
>

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);

>

But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);

>

What am I really supposed to use? How do I get that last pixel
correct?

>

Tom P.

>
What is wrong with e.Graphics.Fill Rectangle( Brushes.White,
e.ClipRectangle );
>
?
Matt

The same thing that's wrong with everything else - it's off by one
pixel.

Tom P.

[Tom P.]

Re: What property defines a controls paint bounds?

On Feb 27, 5:11 pm, "Peter Duniho" <NpOeStPe...@nn owslpianmk.com>
wrote:

On Wed, 27 Feb 2008 13:20:02 -0800, Tom P. <padilla.he...@ gmail.comwrote:

I am creating a custom control and I'm trying to get the painting of
it correct. I'd like to simply use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e);
... or ...
e.Graphics.Fill Rectangle(Brush es.White, ClientRectangle );
... or ...
e.Graphics.Fill Rectangle(Brush es.White, Bounds);

>

But each of those fails to draw a rectangle all the way around (most
are 1 pixel off). Instead I find myself having to use:
e.Graphics.Fill Rectangle(Brush es.White, DisplayRectangl e.X,
DisplayRectangl e.Y, DisplayRectangl e.Width - 1,
DisplayRectangl e.Height - 1);

>

What am I really supposed to use? How do I get that last pixel
correct?

>
Just what you're doing. Either DisplayRectangl e or ClientRectangle are
appropriate, depending on your specific need (by default, they are the
same). And you need to subtract one from the width and height to get the
whole rectangle to draw.
>
This may seem arbitrary, but there's actually a good reason for it.
Graphical coordinates are treated as being the intersection of 0-width
lines in a grid. The pixels are _between_ these lines. A line drawn from
(0,0) to (0,100) for example will fill all of the pixels just to the right
of that 0-width vertical line between those coordinates, inclusive.
>
When you try to draw a rectangle a specific width and height, all of the
pixels are being drawn to the right and below of any coordinate that
describes the rectangle. This means that on the right and bottom of the
rectangle, if you've specified coordinates that are actually the absolute
outer bounds of the area in which the control can draw, those pixels fall
outside of the control and aren't drawn.
>
The fix is to reduce the width and height of the rectangle you're trying
to draw by the width of one pixel, so that the pixels drawn for that
rectangle fall within the control's drawable area.
>
Pete

I guess you're right. There's nothing else I can find to change this.
There should be a "DrawRectan gle" property for this type of
situation. Oh, well... thanks.

Tom P.

[Peter Duniho]

Re: What property defines a controls paint bounds?

On Thu, 28 Feb 2008 10:59:36 -0800, Tom P. <padilla.henry@ gmail.comwrote:

I guess you're right. There's nothing else I can find to change this.
There should be a "DrawRectan gle" property for this type of
situation. Oh, well... thanks.

I don't understand what you mean. There is a DrawRectangle() method, but
it just outlines the rectangle rather than filling it.

There's not an actual problem here with .NET. The only issue is that you
need to comprehend the API differently. Once you understand that
coordinates you provide don't refer to pixels, but rather to the grid
between pixels, everything makes sense.

If you don't understand that, then yes...you'll continue to believe a
problem exists, even though none does.

Pete

[Tom P.]

Re: What property defines a controls paint bounds?

On Feb 28, 1:13 pm, "Peter Duniho" <NpOeStPe...@nn owslpianmk.com>
wrote:

On Thu, 28 Feb 2008 10:59:36 -0800, Tom P. <padilla.he...@ gmail.comwrote:

I guess you're right. There's nothing else I can find to change this.
There should be a "DrawRectan gle" property for this type of
situation. Oh, well... thanks.

>
I don't understand what you mean. There is a DrawRectangle() method, but
it just outlines the rectangle rather than filling it.
>
There's not an actual problem here with .NET. The only issue is that you
need to comprehend the API differently. Once you understand that
coordinates you provide don't refer to pixels, but rather to the grid
between pixels, everything makes sense.
>
If you don't understand that, then yes...you'll continue to believe a
problem exists, even though none does.
>
Pete

I know there is a method DrawRectangle() , but I was talking about a
property that describe the ACTUAL painting region. In the same units,
or relationship, as the method is going to use it. What use have I for
a description of an area I have to adjust before using? Why provide me
with measurements that are close to what I need, but don't finally
describe the area I want? There are no fewer than four rectangles that
describe areas one pixel larger than the Displayed area of a control.
You mean to tell me they couldn't find it in their hearts to provide
one single property that depicts the ACTUAL area that methods like
DrawRectangle() are expecting? It doesn't seem like that big a deal.

Tom P.

[Peter Duniho]

Re: What property defines a controls paint bounds?

On Thu, 28 Feb 2008 13:07:46 -0800, Tom P. <padilla.henry@ gmail.comwrote:

[...]
Understanding all that, what is wrong with saying the PaintingArea is
from (x, y) 0, 0 to (width, height) 99, 99?

Because that would describe an area only 99 pixels wide and 99 pixels high
(9801 pixels total), when in fact the "painting area" (that is, the area
that the control is responsible for painting) is 100 pixels wide by 100
pixels high (10000 pixels total).

>
But I think your last statement gives me some insight into my issue
(and a better way to paint the object, so thank you) The particular
rectangles provided are only 1 pixel too small because the pen I am
using is 1 pixel. They are, in point of fact, "Pen.Width" smaller. I
should not be subtracting 1, I should be subtracting the Pen.Width to
ensure the entire pen falls within the paintable area regardless of
what size the pen is.

Yes, that's exactly right.

To that end I thank you for helping me
understand exactly what is being presented and how to use it.

You're welcome.

Pete