Transparency around non-rectangular (owner draw) ToolTip control? - c#

I'm customizing the appearance of a WinForms ToolTip control by responding to the Draw event. I just want some of the ToolTip's corners to be rounded. I've got everything working such that the first time the ToolTip is displayed, everything looks perfect. On subsequent displays, however, the unfilled areas of my rounded rectangle continue to have what was in the background the first time the ToolTip was displayed.
Screen shot of problem (I don't have rights to put inline apparently):
http://tinypic.com/r/30xa3w9/3
In the picture, you can see the left-over artifacts in the upper-left corner where I would like it to just be transparent (showing the gray background), like this:
tinypic.com/r/mvn8eo/3 (nor rights to add more than one link)
Here is the drawing code:
private void ToolTip_Draw(object sender, DrawToolTipEventArgs args)
{
args.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
var rect = new RectangleF(0, 0, args.Bounds.Width, args.Bounds.Height);
using (var backBrush = new LinearGradientBrush(rect, Color.Silver, this.BackColor, 90))
{
using (var path = GetRoundedRectangle(rect, 10, 4, 4, 1))
{
args.Graphics.FillPath(backBrush, path);
args.DrawText();
}
}
}
The GetRoundedRectangle function (not included) just calculates the appropriate GraphicsPath for the rounded geometry that I want.
I tried adding a call to args.DrawBackground after setting the BackColor to Color.Transparent, but that just filled in the area with the dark gray of the form's background rather than actually being transparent, which I think is the typical "simulated" transparency of WinForms.
As a side note, an non-customized ToolTip with IsBalloon set to true is non-rectangular with correct transparency.
Can anyone suggest a fix for this problem?

Control.Region is what you are looking for. You need to tell the window manager the shape of the tooltip, so background is properly redrawn.

Here is a solution, though imperfect. It uses Graphics.CopyFromScreen to copy the area under the tooltip into the background. Of course, getting the location of the tooltip isn't simple -- hence the reflection and PInvoke call to GetWindowRect.
A remaining glitch is that the background might be wrong while the the tooltip fades out. For example, if you have a button that is colored when the mouse is over it, the tooltip will still have that colored background when you move the mouse off while it fades away. Setting ToolTip.UseFading to false seems to change the frequency of background paints such that it is worse than the fading problem. If the user has disabled eye candy at the OS level, that might also trigger the same paint glitches as having UseFading set to false.
private void ToolTip_Draw2(object sender, DrawToolTipEventArgs args)
{
var graphics = args.Graphics;
var bounds = args.Bounds;
graphics.SmoothingMode = SmoothingMode.AntiAlias;
var windowRect = GetWindowRect();
graphics.CopyFromScreen(windowRect.Left, windowRect.Top, 0, 0, new Size(bounds.Width, bounds.Height));
using (var backBrush = new LinearGradientBrush(bounds, C.Color_LogitechGray2, this.BackColor, 90))
{
using (var path = GetRoundedRectangle(bounds, 10, 4, 4, 1))
{
args.Graphics.FillPath(backBrush, path);
args.DrawText();
}
}
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool GetWindowRect(IntPtr hWnd, ref RECT lpRect);
private Rectangle GetWindowRect()
{
RECT rect = new RECT();
var window = typeof(ToolTip).GetField("window", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(this) as NativeWindow;
GetWindowRect(window.Handle, ref rect);
return rect;
}

Related

Confused about why two Panels work differently

I have a problem that is really confusing me. Let me lay some background. I am trying to develop my own Editor Control. I wish to have a blinking caret, I know I can do this using CreateCaret, ShowCaret ect but this is not how I wish to do it, I wish to implement this myself. My caret does not blink and I cant understand why.
The way I'm trying to implement this is by caching the area below the caret and then display the caret. Then half a second later I repaint the cached data back to the Editor Control therefore effecting a flashing caret. I have tried using just a Graphics Object and a Bitmap for the cache neither worked but I think I know why. So I decided to experiment. I set up one Panel on the Form itself through the Designer and one is handed coded into the Caret class itself. The Panel on the Form works but the Panel encapsulated within the class doesn't and I don't know why. My question is why?
Below is the Code. The BlinkTimer_Tick method just causes the Blink. Paint just Paints the caret, none of this should be hard to understand.
BackupBackground copies the area below the Caret to the cache, while RestoreBackground copies the cache to the Control. Now the problem is if you comment out the lines commented with "Works if this line is commented out" in both methods it all works but when these are not commented it doesn't work the caret does not blink. Both these Panels are set up the same.
private void BlinkTimer_Tick(object sender, EventArgs e)
{
Paint();
_BlinkTimer.Start();
}
private void BackupBackground(Graphics SrcGraph)
{
Form TF = _Parent.FindForm() as Form;
Panel P = TF.Controls["_TestPanel"] as Panel;
P = _Buffer; // Works if this line is Commentted out
Graphics DestGraph = P.CreateGraphics();
IntPtr SrcHDC = SrcGraph.GetHdc();
IntPtr DestHDC = DestGraph.GetHdc();
BitBlt(DestHDC, 0, 0, _Size.Width, _Size.Height,
SrcHDC, _Location.X, _Location.Y, TernaryRasterOperations.SRCCOPY);
DestGraph.ReleaseHdc(DestHDC);
SrcGraph.ReleaseHdc(SrcHDC);
}
private void RestoreBackground(Graphics DestGraph)
{
Form TF = _Parent.FindForm() as Form;
Panel P = TF.Controls["_TestPanel"] as Panel;
P = _Buffer; // Works if this line is Commentted out
Graphics SrcGraph = P.CreateGraphics();
IntPtr SrcHDC = SrcGraph.GetHdc();
IntPtr DestHDC = DestGraph.GetHdc();
BitBlt(DestHDC, _Location.X, _Location.Y, _Size.Width, _Size.Height,
SrcHDC, 0, 0, TernaryRasterOperations.SRCCOPY);
DestGraph.ReleaseHdc(DestHDC);
SrcGraph.ReleaseHdc(SrcHDC);
}
internal void Paint()
{
Graphics Graph = _Parent.CreateGraphics();
if (!_BlinkOn)
{
// Restore Graphics from Backup
RestoreBackground(Graph);
_BlinkOn = true;
}
else
{
// Backup Graphics
Graph.Flush();
BackupBackground(Graph);
// Draw Caret
using (SolidBrush P = new SolidBrush(Color.Black))
{
Graph.FillRectangle(P, new Rectangle(_Location, _Size));
}
_BlinkOn = false;
}
}
The Caret should flash in both circumstances as I change nothing really but it only flashes when I use the Panel on the Form.
Note: I do not intend to use a Panel for the cache I was just experimenting and found this behavior and its weird, so I need to know.
Thanks Danny.

Recoloring TabControl

I have a tab control which I want to customize. To be more specific, I want to change the color of the tab page header, as well as the color of that white line around the tab page (check first picture).
I thought of using a custom renderer to do this (similar to recoloring a menu strip, for example), but I'm not sure how to do this. I've also read that setting the DrawMode to OwnerDrawFixed may do this, but using this option makes the the tab control look as if my program was made in the '90s (check second picture).
What I really want to do is to keep the tabs simple and flat and change their color. Check the way tabs are in Visual Studio as an example (check third picture).
Any ideas?
Edit: Another picture of the tab page so that it's more clear what this "white line" is.
When you use OwnerDrawFixed it means you will supply the drawing code. If you did not hook up and use the DrawItem event, nothing gets drawn. This will look much the same as yours at design time, because the event is not firing. For design time painting, you'd have to subclass the control and use OnDrawItem.
// colors to use
private Color[] TColors = {Color.Salmon, Color.White, Color.LightBlue};
private void tabControl1_DrawItem(object sender, DrawItemEventArgs e)
{
// get ref to this page
TabPage tp = ((TabControl)sender).TabPages[e.Index];
using (Brush br = new SolidBrush(TColors[e.Index]))
{
Rectangle rect = e.Bounds;
e.Graphics.FillRectangle(br, e.Bounds);
rect.Offset(1, 1);
TextRenderer.DrawText(e.Graphics, tp.Text,
tp.Font, rect, tp.ForeColor);
// draw the border
rect = e.Bounds;
rect.Offset(0, 1);
rect.Inflate(0, -1);
// ControlDark looks right for the border
using (Pen p = new Pen(SystemColors.ControlDark))
{
e.Graphics.DrawRectangle(p, rect);
}
if (e.State == DrawItemState.Selected) e.DrawFocusRectangle();
}
}
basic result:
The tab thumb looks a bit cramped to me and not as tall as the default. So, I added a TFontSize to draw the text at a different size than the Font.
Set the TabControl.Font to 10 (which seems to be plenty), so that Windows draws a slightly larger thumb/header. If you still draw the text at the default 8.25, there is more room:
private float TFontSize = 8.25F; // font drawing size
...
using (Font f = new Font(tp.Font.FontFamily,TFontSize))
{
// shift for a gutter/padding
rect.Offset(1, 1);
TextRenderer.DrawText(e.Graphics, tp.Text,
f, rect, tp.ForeColor);
}
One thing you will loose this way is the VisualStyles effect, but they would seem to clash with colored tabs anyway.

PictureBox performing unwanted scaling C#

I currently have a windows form app with a pictureBox in the middle of it which i am drawing various images too. The images are drawing fine except for the fact that they are all being scaled up by exactly 25%. I should also add that i am drawing everything inside a Paint method, using the PaintEventArgs to get the graphics device.
Ive made sure the SizeMode is set to Normal, ive checked over and over that the scale factor of the graphics object is 1 and all the image objects that i pass to the paint method are of the size they should be, but when they get drawn they are a different size.
I have until now just been calling g.drawImage(image, Rectangle) and passing the width and height of the image as the width and height of the Rectangle so that they are forced to be drawn at the correct size but i feel that this should be a short term fix and i am overlooking something simple.
Any help would be great, thanks in advance.
Code is as follows (only the important bits):
public class Level : PictureBox
{
...
private Image image;
...
public Level(TabPage parent, Panel propertiesPanel, ItemManager items, string levelName)
{
...
image = Image.FromFile(#"Levels/" + levelName);
Size = image.Size;
SizeMode = PictureBoxSizeMode.Normal;
MouseClick += new MouseEventHandler(level_MouseClick);
MouseMove += new MouseEventHandler(level_MouseMove);
Paint += new PaintEventHandler(level_Paint);
Invalidate();
}
private void level_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
//With the rectangle fix (drawing to correct size)
g.DrawImage(image, new Rectangle(0, 0, image.Size.Width, image.Size.Height));
////Without the fix (as i thought it should be be this is where it scales it)
//g.DrawImage(image, new Point(0, 0));
drawPlacedItems(g);
drawItemPreview(g);
}
This sounds like the HorizontalResolution and VerticalResolution properties of your image are being applied when you don't want them to, modify your code as per Jeremy's link to Image sizing issue in bitmap that ensures that HorizontalResolution and VerticalResolution are reset or ignored before calling DrawImage.

Clear background of transparent user control

I'm working on ImageButton, in which I paint every state(i've got several images for each state) of this button (like mouseOver, mouseDown etc.).
I've made control transparent using this code:
public ImageButton()
{
InitializeComponent();
this.SetStyle(ControlStyles.Opaque, true);
this.SetStyle(ControlStyles.OptimizedDoubleBuffer, false);
}
protected override CreateParams CreateParams
{
get
{
CreateParams parms = base.CreateParams;
parms.ExStyle |= 0x20;
return parms;
}
}
But there's a problem, after few switches of state, corners becoming sharp and ugly, to solve this problem I need to clear background, but if my control is transparent then it's impossible.
I've tried this solution: Clearing the graphics of a transparent panel C#
but it's slow and makes control flickering.
Do you have any ideas how to clear this background and keep transparency of control?
Ok, I've solved this problem.
I've worked around it by setting control as not transparent and I draw canvas which is under my control, as background of my ImageButton.
Solution (in Paint event):
//gets position of button and transforms it to point on whole screen
//(because in next step we'll get screenshot of whole window [with borders etc])
Point btnpos = this.Parent.PointToScreen(new Point(Location.X, Location.Y));
//now our point will be relative to the edges of form
//[including borders, which we'll have on our bitmap]
if (this.Parent is Form)
{
btnpos.X -= this.Parent.Left;
btnpos.Y -= this.Parent.Top;
}
else
{
btnpos.X = this.Left;
btnpos.Y = this.Top;
}
//gets screenshot of whole form
Bitmap b = new Bitmap(this.Parent.Width, this.Parent.Height);
this.Parent.DrawToBitmap(b, new Rectangle(new Point(0, 0), this.Parent.Size));
//draws background (which simulates transparency)
e.Graphics.DrawImage(b,
new Rectangle(new Point(0, 0), this.Size),
new Rectangle(btnpos, this.Size),
GraphicsUnit.Pixel);
//do whatever you want to draw your stuff
PS. It doesn't work in designtime.

WinForms system-renderer Toolstrip item hover effect on button controls

If you take a look at the attached image, is there a way to get the drawing logic for this hover effect from the system renderer of the standard WinForms toolstrip ?
http://imageshack.us/photo/my-images/10/toolstriphovereffect.jpg/
EDIT: Anyway, I've manually implemented this with images, but if anyone comes here with a solution, please post.
Maybe this code helps. It draws red circle with black border around toolstripbutton when mouse is over it.
Set your toolstrip properties:
//Set render mode to professional
myToolStrip.RenderMode = ToolStripRenderMode.Professional;
//Assign new instance of your custom renderer
myToolStrip.Renderer = new MyCustomRenderer();
Custom renderer class:
public class MyCustomRenderer : ToolStripProfessionalRenderer
{
protected override void OnRenderButtonBackground(ToolStripItemRenderEventArgs e)
{
if (!e.Item.Selected)
base.OnRenderButtonBackground(e);
else
{
Rectangle rectangle = new Rectangle(0, 0, e.Item.Size.Width - 1, e.Item.Size.Height - 1);
//Draw red circle
e.Graphics.FillEllipse(Brushes.Red, rectangle);
//Draw black border
e.Graphics.DrawEllipse(Pens.Black, rectangle);
}
}
}

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