Collapsible Splitter control in C#

Introduction

This control was modeled from the collapsible splitter used in the Mozilla web browser, but with some added functionality. This control allows a linked form control to be dynamically expanded and collapsed by clicking on the splitter control button, and resized by dragging the splitter. Additionally, there is an option to expanded or contract the parent form so that the control to expand doesn't take any further form area.

How it works

The CollapsibleSplitter derives from the System.Windows.Forms.Splitter class, working with 2 overrides, mouse event handlers, and exposing 4 new properties. The code is relatively straight-forward, and is well commented. The only code that I will cover here is the control painting and interaction with the base splitter control.

In creating the control, I first started by creating a new derived class with Stephen Toub's DeriveClass utility. The next step was to draw the control surface, first by finding the clip rectangle for the base splitter and then defining a new rectangle located in the vertical center of the splitter for the collapser control.

protected override void OnPaint(PaintEventArgs e)
{
    // force the width to 8px so that everything
    // always draws correctly
    this.Width = 8;

    // create a Graphics object
    Graphics g = e.Graphics;

    // find the rectangle for the splitter and paint it
    Rectangle r = this.ClientRectangle; // fixed in version 1.1
    g.FillRectangle(new SolidBrush(this.BackColor), r);

    // create a new rectangle in the vertical center 
    // of the splitter for our collapse control button
    rr = new Rectangle(r.X, (int) r.Y + ((r.Height - 115)/2),
        8, 115);

    // draw the background color for our control image
    if(hot)
        g.FillRectangle(new SolidBrush(hotColor), 
            new Rectangle(rr.X + 1, rr.Y, 6, 115));
    else
        g.FillRectangle(new SolidBrush(this.BackColor), 
            new Rectangle(rr.X + 1, rr.Y, 6, 115));

    // draw the top & bottom lines for our control image
    g.DrawLine(new Pen(SystemColors.ControlDark, 1), 
        rr.X + 1, rr.Y, rr.X + rr.Width - 2, rr.Y);
    g.DrawLine(new Pen(SystemColors.ControlDark, 1), 
        rr.X + 1, rr.Y + rr.Height, rr.X + rr.Width - 2, 
        rr.Y + rr.Height);

    // draw the arrows for our control image
    // the ArrowPointArray is a point array that 
    // defines an arrow shaped polygon
    g.FillPolygon(new SolidBrush(SystemColors.ControlDarkDark), 
        ArrowPointArray(rr.X + 2, rr.Y + 3));

    g.FillPolygon(new SolidBrush(SystemColors.ControlDarkDark), 
        ArrowPointArray(rr.X + 2, rr.Y + rr.Height - 9));

    // draw the dots for our control image using a loop
    int x = rr.X + 3;
    int y = rr.Y + 14;

    // Visual Styles added in version 1.1
    switch(visualStyle)
    {
    case VisualStyles.Mozilla:
        for(int i=0; i < 30; i++)
        {
            // light dot
            g.DrawLine(
                new Pen(SystemColors.ControlLightLight), 
                x, y + (i*3), x+1, y + 1 + (i*3));

            // dark dot
            g.DrawLine(
                new Pen(SystemColors.ControlDarkDark), 
                x+1, y + 1 + (i*3), x+2, y + 2 + (i*3));

            // overdraw the background color as we actually 
            // drew 2px diagonal lines, not just dots..
            if(hot)
                g.DrawLine(new Pen(hotColor), 
                    x+2, y + 1 + (i*3), x+2, y + 2 + (i*3));
            else
                g.DrawLine(new Pen(this.BackColor), 
                    x+2, y + 1 + (i*3), x+2, y + 2 + (i*3));
        }
        break;

    case VisualStyles.DoubleDots:
        for(int i=0; i < 30; i++)
        {
            // light dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlLightLight), 
                x, y + 1 + (i*3), 1, 1 );

            // dark dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlDark), 
                x - 1, y +(i*3), 1, 1 );

            i++;

            // light dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlLightLight), 
                x + 2, y + 1 + (i*3), 1, 1 );

            // dark dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlDark), 
                x + 1, y  + (i*3), 1, 1 );
        }
        break;

    case VisualStyles.Win9x:
        g.DrawLine(new Pen(SystemColors.ControlLightLight), 
            x, y, x + 2, y);
        g.DrawLine(new Pen(SystemColors.ControlLightLight), 
            x, y, x,y + 90);
        g.DrawLine(new Pen(SystemColors.ControlDark), 
            x + 2, y, x + 2, y + 90);
        g.DrawLine(new Pen(SystemColors.ControlDark), 
            x, y + 90, x + 2, y + 90);
        break;

    case VisualStyles.XP:
        for(int i=0; i < 18; i++)
        {
            // light dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlLight), 
                x, y + (i*5), 2, 2 );

            // light light dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlLightLight), 
                x + 1, y + 1 + (i*5), 1, 1 );

            // dark dark dot
            g.DrawRectangle(
                new Pen(SystemColors.ControlDarkDark), 
                x, y +(i*5), 1, 1 );

            // dark fill
            g.DrawLine(
                new Pen(SystemColors.ControlDark), 
                x, y + (i*5), x, y + (i*5) + 1);

            g.DrawLine(
                new Pen(SystemColors.ControlDark), 
                x, y + (i*5), x + 1, y + (i*5));
        }
        break;

    case VisualStyles.Lines:
        for(int i=0; i < 44; i++)
        {
            g.DrawLine(new Pen(SystemColors.ControlDark), 
                x, y + (i*2), x + 2, y + (i*2));
        }

        break;
    }

    // dispose the Graphics object
    g.Dispose();
}

The control rectangle is used in the MouseMove event to determine if the cursor is within the control area (hot), or in the base controls splitter area. Once we know whether the cursor is in the 'hot' area we can change various aspects of the control: use a highlighted background color, ignore or pass on the MouseDown event, and also set the appropriate mouse cursor.

// this method was updated in version 1.11 to fix 
// a flickering problem discovered by John O'Byrne
private void OnMouseMove(object sender, MouseEventArgs e)
{
    // check to see if the mouse cursor position is within 
    // the bounds of our control
    if(e.X >= rr.X && e.X <= rr.X + rr.Width && 
        e.Y >= rr.Y && e.Y <= rr.Y + rr.Height)
    {
        if(!hot)
        {
            hot = true;
            this.Cursor = Cursors.Hand;
            this.Refresh();
        }
    }
    else
    {
        if(hot)
        {
            hot = false;
            this.Refresh();
        }

        if(!controlToHide.Visible)
            this.Cursor = Cursors.Default;
        else
            this.Cursor = Cursors.VSplit;
    }
}

protected override void OnMouseDown(MouseEventArgs e)
{
    // if the hider control isn't hot, 
    // let the base resize action occur
    if(!hot && !collapsed)
        base.OnMouseDown(e);
}

Using the control

The CollapsibleSplitter control can be added to the toolbox using the pre-compiled dll in the demo application, or simply copy the class into your project and manually reference it in your code.

To Add the Collapsible Splitter to your VS.Net toolbox, follow these steps:

Right-click on the VS.Net Toolbox and select "Customize Toolbox..."
Select the ".Net Framework Components" tab, and click the "Browse.." button
Browse to and open the "CollapsibleSplitter.dll" file from the demo application archive
Click OK to add Collapsible Splitter control to your Toolbox.

Once you have it on a form, set the Dock property, and then set the ControlToHideproperty so that the splitter knows which form control to interact with. All properties specific to the collapsing behaviour can be found under the Collapsing Options group in the properties window. Once created on your form, the view state can be programmatically toggled by calling the ToggleState method, and the current state can be retrieved from the IsCollapsed property.

I hope you find this control useful, and if you improve this control, please email me the updated source. If you have any comments or suggestions, please post your thoughts in the feedback section below.

Updates

Version 1.1 Changes:

OnPaint is now overridden instead of being a handled event, and the entire splitter is now painted rather than just the collapser control
The splitter rectangle is now correctly defined
The Collapsed property was renamed to IsCollapsed, and the code changed so that no value needs to be set
New visual styles added: Win9x, XP, DoubleDots and Lines

Version 1.11 Changes:

The OnMouseMove event handler was updated to address a flickering issue discovered by John O'Byrne

Version 1.2 Changes:

Added support for Horizontal Splitters

Version 1.3 Changes: (24 Aug 2003)

Added an optional 3D border
General code and comment cleaning
Flagged assembly with the CLSCompliant attribute
Added a simple designer class to filter unwanted properties
Added support for inclusion as a VS.Net ToolBox control
Added a ToolBox bitmap
Removed extraneous overrides
Added summaries
Removed the ParentFolder from public properties - this is now set automatically in the OnHandleCreated event
Added expand/collapse animation code

License

This article, along with any associated source code and files, is licensed under The Microsoft Public License (Ms-PL)

About the Author

Furty

Web Developer

Thailand

Member

Furty will code for food.

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Do not dispose e.Graphics in Paint event

Member 1430126

8:09 17 Aug '11

You should not dispose of the Graphics object in the Paint event. See: http://stackoverflow.com/questions/4316149/c-is-it-neccesary-to-dispose-of-a-graphics-element-inside-a-custom-control[^] Also please add: this.SetStyle(ControlStyles.UserPaint \| ControlStyles.AllPaintingInWmPaint \| ControlStyles.OptimizedDoubleBuffer, true); In the constructor to eliminate flicker
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License

aldo hexosa

17:08 6 Jul '09

Nice job. I like your Collapsible Splitter. May I use it in my commercial application?
Sign In·View Thread·Permalink	1.00/5 (2 votes)

update to new version please

cvckillern

3:27 8 May '09

it would be nice if you could update Collapsible Splitter control to the newest version
Sign In·View Thread·Permalink	2.00/5 (1 vote)

memory management bug

zxcv0938512485

10:57 22 Sep '07

use Dispose!!! (override Dispose, dispose graphic objects ...)
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Re: memory management bug

Member 3427403

13:02 26 Jan '09

This is a fix for lack of dispose in OnPaint

// OnPaint is now an override rather than an event in version 1.1
        protected override void OnPaint(PaintEventArgs e)
        {
            // create a Graphics object
            using (Graphics g = e.Graphics)
            {
                Pen pen_controlLightLight = new Pen(SystemColors.ControlLightLight);
                Pen pen_controlLight = new Pen(SystemColors.ControlLight);
                Pen pen_controlDark = new Pen(SystemColors.ControlDark);
                Pen pen_backColor = new Pen(this.BackColor);
                Pen pen_hotColor = new Pen(this.hotColor);
                Pen pen_controlDarkDark = new Pen(SystemColors.ControlDarkDark);
 
                Brush brush_controlDark = new SolidBrush(SystemColors.ControlDark);
                Brush brush_controlDarkDark = new SolidBrush(SystemColors.ControlDarkDark);
                Brush brush_backColor = new SolidBrush(this.BackColor);
                Brush brush_hotColor = new SolidBrush(this.hotColor);
 
                // find the rectangle for the splitter and paint it
                Rectangle r = this.ClientRectangle; // fixed in version 1.1
                g.FillRectangle(brush_backColor, r);
 
                #region Vertical Splitter
                // Check the docking style and create the control rectangle accordingly
                if (this.Dock == DockStyle.Left || this.Dock == DockStyle.Right)
                {
                    // create a new rectangle in the vertical center of the splitter for our collapse control button
                    rr = new Rectangle(r.X, (int)r.Y + ((r.Height - 115) / 2), 8, 115);
                    // force the width to 8px so that everything always draws correctly
                    this.Width = 8;
 
                    // draw the background color for our control image
                    if (hot)
                    {
                        g.FillRectangle(brush_hotColor, new Rectangle(rr.X + 1, rr.Y, 6, 115));
                    }
                    else
                    {
                        g.FillRectangle(brush_backColor, new Rectangle(rr.X + 1, rr.Y, 6, 115));
                    }
 
                    // draw the top & bottom lines for our control image
                    using (Pen pn = new Pen(SystemColors.ControlDark, 1))
                    {
                        g.DrawLine(pn, rr.X + 1, rr.Y, rr.X + rr.Width - 2, rr.Y);
                        g.DrawLine(pn, rr.X + 1, rr.Y + rr.Height, rr.X + rr.Width - 2, rr.Y + rr.Height);
                    }
 
                    if (this.Enabled)
                    {
                        // draw the arrows for our control image
                        // the ArrowPointArray is a point array that defines an arrow shaped polygon
                        g.FillPolygon(brush_controlDarkDark, ArrowPointArray(rr.X + 2, rr.Y + 3));
                        g.FillPolygon(brush_controlDarkDark, ArrowPointArray(rr.X + 2, rr.Y + rr.Height - 9));
                    }
 
                    // draw the dots for our control image using a loop
                    int x = rr.X + 3;
                    int y = rr.Y + 14;
 
                    // Visual Styles added in version 1.1
                    switch (visualStyle)
                    {
                        case VisualStyles.Mozilla:
 
                            for (int i = 0; i < 30; i++)
                            {
                                // light dot
                                g.DrawLine(pen_controlLightLight, x, y + (i * 3), x + 1, y + 1 + (i * 3));
                                // dark dot
                                g.DrawLine(pen_controlDarkDark, x + 1, y + 1 + (i * 3), x + 2, y + 2 + (i * 3));
                                // overdraw the background color as we actually drew 2px diagonal lines, not just dots
                                if (hot)
                                {
                                    g.DrawLine(pen_hotColor, x + 2, y + 1 + (i * 3), x + 2, y + 2 + (i * 3));
                                }
                                else
                                {
                                    g.DrawLine(pen_backColor, x + 2, y + 1 + (i * 3), x + 2, y + 2 + (i * 3));
                                }
                            }
                            break;
 
                        case VisualStyles.DoubleDots:
                            for (int i = 0; i < 30; i++)
                            {
                                // light dot
                                g.DrawRectangle(pen_controlLightLight, x, y + 1 + (i * 3), 1, 1);
                                // dark dot
                                g.DrawRectangle(pen_controlDark, x - 1, y + (i * 3), 1, 1);
                                i++;
                                // light dot
                                g.DrawRectangle(pen_controlLightLight, x + 2, y + 1 + (i * 3), 1, 1);
                                // dark dot
                                g.DrawRectangle(pen_controlDark, x + 1, y + (i * 3), 1, 1);
                            }
                            break;
 
                        case VisualStyles.Win9x:
 
                            g.DrawLine(pen_controlLightLight, x, y, x + 2, y);
                            g.DrawLine(pen_controlLightLight, x, y, x, y + 90);
                            g.DrawLine(pen_controlDark, x + 2, y, x + 2, y + 90);
                            g.DrawLine(pen_controlDark, x, y + 90, x + 2, y + 90);
                            break;
 
                        case VisualStyles.XP:
 
                            for (int i = 0; i < 18; i++)
                            {
                                // light dot
                                g.DrawRectangle(pen_controlLight, x, y + (i * 5), 2, 2);
                                // light light dot
                                g.DrawRectangle(pen_controlLightLight, x + 1, y + 1 + (i * 5), 1, 1);
                                // dark dark dot
                                g.DrawRectangle(pen_controlDarkDark, x, y + (i * 5), 1, 1);
                                // dark fill
                                g.DrawLine(pen_controlDark, x, y + (i * 5), x, y + (i * 5) + 1);
                                g.DrawLine(pen_controlDark, x, y + (i * 5), x + 1, y + (i * 5));
                            }
                            break;
 
                        case VisualStyles.Lines:
 
                            for (int i = 0; i < 44; i++)
                            {
                                g.DrawLine(pen_controlDark, x, y + (i * 2), x + 2, y + (i * 2));
                            }
 
                            break;
                    }
 
                    // Added in version 1.3
                    if (this.borderStyle != System.Windows.Forms.Border3DStyle.Flat)
                    {
                        // Paint the control border
                        ControlPaint.DrawBorder3D(e.Graphics, this.ClientRectangle, this.borderStyle, Border3DSide.Left);
                        ControlPaint.DrawBorder3D(e.Graphics, this.ClientRectangle, this.borderStyle, Border3DSide.Right);
                    }
                }
 
                #endregion
 
                // Horizontal Splitter support added in v1.2

                #region Horizontal Splitter
 
                else if (this.Dock == DockStyle.Top || this.Dock == DockStyle.Bottom)
                {
                    // create a new rectangle in the horizontal center of the splitter for our collapse control button
                    rr = new Rectangle((int)r.X + ((r.Width - 115) / 2), r.Y, 115, 8);
                    // force the height to 8px
                    this.Height = 8;
 
                    // draw the background color for our control image
                    if (hot)
                    {
                        g.FillRectangle(brush_hotColor, new Rectangle(rr.X, rr.Y + 1, 115, 6));
                    }
                    else
                    {
                        g.FillRectangle(brush_backColor, new Rectangle(rr.X, rr.Y + 1, 115, 6));
                    }
 
                    // draw the left & right lines for our control image
                    using (Pen pn = new Pen(SystemColors.ControlDark, 1))
                    {
                        g.DrawLine(pn, rr.X, rr.Y + 1, rr.X, rr.Y + rr.Height - 2);
                        g.DrawLine(pn, rr.X + rr.Width, rr.Y + 1, rr.X + rr.Width, rr.Y + rr.Height - 2);
                    }
                    if (this.Enabled)
                    {
                        // draw the arrows for our control image
                        // the ArrowPointArray is a point array that defines an arrow shaped polygon
                        g.FillPolygon(brush_controlDarkDark, ArrowPointArray(rr.X + 3, rr.Y + 2));
                        g.FillPolygon(brush_controlDarkDark, ArrowPointArray(rr.X + rr.Width - 9, rr.Y + 2));
                    }
 
                    // draw the dots for our control image using a loop
                    int x = rr.X + 14;
                    int y = rr.Y + 3;
 
                    // Visual Styles added in version 1.1
                    switch (visualStyle)
                    {
                        case VisualStyles.Mozilla:
 
                            for (int i = 0; i < 30; i++)
                            {
                                // light dot
                                g.DrawLine(pen_controlLightLight, x + (i * 3), y, x + 1 + (i * 3), y + 1);
                                // dark dot
                                g.DrawLine(pen_controlDarkDark, x + 1 + (i * 3), y + 1, x + 2 + (i * 3), y + 2);
                                // overdraw the background color as we actually drew 2px diagonal lines, not just dots
                                if (hot)
                                {
                                    g.DrawLine(pen_hotColor, x + 1 + (i * 3), y + 2, x + 2 + (i * 3), y + 2);
                                }
                                else
                                {
                                    g.DrawLine(pen_backColor, x + 1 + (i * 3), y + 2, x + 2 + (i * 3), y + 2);
                                }
                            }
                            break;
 
                        case VisualStyles.DoubleDots:
 
                            for (int i = 0; i < 30; i++)
                            {
                                // light dot
                                g.DrawRectangle(pen_controlLightLight, x + 1 + (i * 3), y, 1, 1);
                                // dark dot
                                g.DrawRectangle(pen_controlDark, x + (i * 3), y - 1, 1, 1);
                                i++;
                                // light dot
                                g.DrawRectangle(pen_controlLightLight, x + 1 + (i * 3), y + 2, 1, 1);
                                // dark dot
                                g.DrawRectangle(pen_controlDark, x + (i * 3), y + 1, 1, 1);
                            }
                            break;
 
                        case VisualStyles.Win9x:
 
                            g.DrawLine(pen_controlLightLight, x, y, x, y + 2);
                            g.DrawLine(pen_controlLightLight, x, y, x + 88, y);
                            g.DrawLine(pen_controlDark, x, y + 2, x + 88, y + 2);
                            g.DrawLine(pen_controlDark, x + 88, y, x + 88, y + 2);
                            break;
 
                        case VisualStyles.XP:
 
                            for (int i = 0; i < 18; i++)
                            {
                                // light dot
                                g.DrawRectangle(pen_controlLight, x + (i * 5), y, 2, 2);
                                // light light dot
                                g.DrawRectangle(pen_controlLightLight, x + 1 + (i * 5), y + 1, 1, 1);
                                // dark dark dot
                                g.DrawRectangle(pen_controlDarkDark, x + (i * 5), y, 1, 1);
                                // dark fill
                                g.DrawLine(pen_controlDark, x + (i * 5), y, x + (i * 5) + 1, y);
                                g.DrawLine(pen_controlDark, x + (i * 5), y, x + (i * 5), y + 1);
                            }
                            break;
 
                        case VisualStyles.Lines:
 
                            for (int i = 0; i < 44; i++)
                            {
                                g.DrawLine(pen_controlDark, x + (i * 2), y, x + (i * 2), y + 2);
                            }
 
                            break;
                    }
 
                    // Added in version 1.3
                    if (this.borderStyle != System.Windows.Forms.Border3DStyle.Flat)
                    {
                        // Paint the control border
                        ControlPaint.DrawBorder3D(e.Graphics, this.ClientRectangle, this.borderStyle, Border3DSide.Top);
                        ControlPaint.DrawBorder3D(e.Graphics, this.ClientRectangle, this.borderStyle, Border3DSide.Bottom);
                    }
                }
 
                #endregion
 
                else
                {
                    throw new Exception("The Collapsible Splitter control cannot have the Filled or None Dockstyle property");
                }
 
                // dispose the Graphics objects
                pen_controlLightLight.Dispose();
                pen_controlLight.Dispose();
                pen_controlDark.Dispose();
                pen_backColor.Dispose();
                pen_hotColor.Dispose();
                pen_controlDarkDark.Dispose();
 
                brush_controlDark.Dispose();
                brush_controlDarkDark.Dispose();
                brush_backColor.Dispose();
                brush_hotColor.Dispose();
            }
        }

Re: memory management bug

tr0217

18:58 8 Feb '11

Very usefull, and I want to use it in my project. To be fankly, it do exists a memory-leak problem in the OnPaint method. I also encountered such kind of problem before. An experienced programmer told me that all graphic object(Pen, Brush, Font and what not) need to be disposed.
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Re: memory management bug

Member 1430126

8:12 17 Aug '11

This is only true if you create the Graphics object using Graphics.FromXxxxx()
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New implementation for SplitterContainter

marioz8

9:05 14 Sep '07

Hi, I have been tryied to implement a similar component when I lock your. So I get some methods from our implementation but inheriting from SplitterContainer. I want to know if I can do a article discribing the changes that I made based on your component a submite the source code for other developers. Mário Santos, Brazil.
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Re: New implementation for SplitterContainter

Furty

14:10 14 Sep '07

So long as you link back to this article, go for it Mário.
Sign In·View Thread·Permalink	2.00/5 (1 vote)

AnimationDelay does nothing

jbshaler

5:36 11 Jul '07

Thanks a lot for this control! It's really nice (although it seems like it should still work like a normal splitter when the control to collapse is not set -- I wanted it originally just for the improved look).

One thing: the Interval property of the animation timer is only set in the constructor, so setting the AnimationDelay property does nothing. Add the following line in the set accessor of AnimationDelay:

animationTimer.Interval = value;

Still, it doesn't change much to go shorter than the default of 20 due to the timer resolution, and I doubt anyone is going to want to make it longer (more choppy motion).

Re: AnimationDelay does nothing

orientalCSharp

22:49 20 Jun '10

It should set "this.animationTimer.Interval = value;" in the Property of AnimationDelay Thus it looks like follows: [Bindable(true), Category("Collapsing Options"), DefaultValue("20"), Description("The delay in millisenconds between animation steps")] public int AnimationDelay { get { return this.animationDelay; } set { this.animationDelay = value; this.animationTimer.Interval = value; } }
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NEWBE

Lonnie1

10:04 17 Nov '06

Can I use a button to do open/close the panels or do I have to use the toolbar? If I can use the button, how would I code it? This is my first time using c and I need all the help I can get. Thanks
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Access Violation Exception

Louis-Philippe Carignan

6:01 2 Nov '06

Hi,

We have integrated the collapsible splitter into our application. It worked fine under .NET 1.1 but we now have issues with it under 2.0. The problem seems random as we can't find a pattern to reproduce it. It even happens when the form with the splitter in it is minimized. We sometimes get the following error message when the splitter paints itself.

System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
at System.Drawing.SafeNativeMethods.Gdip.GdipDrawLineI(HandleRef graphics, HandleRef pen, Int32 x1, Int32 y1, Int32 x2, Int32 y2)
at System.Drawing.Graphics.DrawLine(Pen pen, Int32 x1, Int32 y1, Int32 x2, Int32 y2)
at CollapsibleSplitter.OnPaint(PaintEventArgs e) in C:\DEV\APTS\NJFLib.Controls\NJFLib.Controls.CollapsibleSplitter.cs:line 601
at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer, Boolean disposeEventArgs)
at System.Windows.Forms.Control.WmPaint(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run()

Any ideas on why this happen?

Nice one dude !!

scanner777

22:48 16 Sep '06


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A problem used in MDI application

grrrrr

14:32 14 Dec '05

For example,I have a treeview docked in the left which is the hide control of the Collapsible Splitter control "CollapsibleSplitter1". Then it works well. But now I want to hide the ChildForm, and expand the threeview. How should I do?
Sign In·View Thread·Permalink	4.20/5 (2 votes)

I added an event "StateChanged" into the control

Wayne Wood

5:28 13 Sep '05

you know, sometimes we need to update other UI elements when the splitter folded or unfolded, but i found no event notification was raised when the state toggled in this control. then i added one by myself, which is very simple. i'm fresh here, so i dont know how to post code or upload attachment package who can help me to post my modification? thanks
Sign In·View Thread·Permalink	1.50/5 (2 votes)

Memory problem

kanaan81

5:09 18 Jul '05

Hi I think you have a problem in your code, because in the demo exe, every time we use your splitter in the exe the memory usage increase(you can monitor the memory usage with windows task manager) I think your allocate variables without deallocation.. kanaan
Sign In·View Thread·Permalink	5.00/5 (1 vote)

TabPages

Jon Lea

12:21 17 Mar '05

Furty - nice control and I have things working pretty much the way I want except that when I collapse your splitter to the right edge of a tabPage (this splitter hides panel4 docked to the right side) I no longer can see the splitter. I have a collapsible splitter on the left side (hidding panel1 docked to the left) and a splitter on the top (this hides panel2) and they work fine.

Any idea why the right side is giving me problems?

The app is a Form with a tabSheet and two tab pages. The second tab page is where the collapsible splitters are and the four panes:

panel2
panel1 VCS HCS VCS panel4
panel3

Thanks.

Jon.

Re: TabPages

Furty

17:13 17 Mar '05

Hi Jon, It sounds like you've got the second VCS as a child of Panel4, rather than a child of the TabPage itself. Failing this, it could be a z-order issue. As noted in this[^] thread, all such issues usually end up being a simple heirarchy problem.
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Works fine on Form, buggy on Control

Lee Grissom

9:08 3 Mar '05

When we put the splitter on a form, it works as expected. However, when we put it on a custom control (or standard panel), it has problems. It correctly draws itself, and correctly hides/shows the "controlToHide". However, the location of the splitter does not move. When we place everything on a Panel, it moves, but the "dark gray" outline of the "old" position remains. Our guess is that there is a bunch of extra processing that occurs behind the scenes on the Form vs. a control. Any ideas on how we might get this to work correctly? Thanks.

Re: Works fine on Form, buggy on Control

PunCha

23:52 13 Feb '07

Yeah! I met the same problem:

Please allow me to use the term "Shadow" to describe the stuff which I really didn't know how to name it. The term "Shadow" is: When you press the splitter( don't release you mouse ) or drag the splitter, you can see a "Shadow" which helps to identify the position of the splitter.

----------------------------------------------
OK, here is the issue:
1, I set the UseAnimation to "False", Mozila style and run the application.
2, When I click the splitter, everything is OK except the "Shadow" still left.
3, And I replace your splitter with .Net 2.0's. The sistuation still happens. So I think it's Windows's fault.

Release PunCha's Power!

Re: Works fine on Form, buggy on Control

aldo hexosa

17:26 15 Feb '09

I think it's splitter's bug. i also met this shadow when using splitter with user control in panel. anyone please help
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collapsible splitter button - able to drag?

Johnny O

12:04 23 Feb '05

It appears you can't drag/resize the splitter by attempting to "grab" the splitter button. The button only allows clicking to hide a control. It would be nice to allow re-sizing as well but didn't find a way.
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Re: collapsible splitter button - able to drag?

PunCha

23:40 13 Feb '07

You can made the following changes to the member function OnMouseDown:

protected override void OnMouseDown(MouseEventArgs e)
{
    // if the hider control isn't hot, let the base resize action occur
    if (this.controlToHide != null)
    {
        if (/*!this.hot &&*/ this.controlToHide.Visible)
        {
            base.OnMouseDown(e);
        }
    }
}

Release PunCha's Power!

Offscreen Drawing...

TJoe

1:56 23 Dec '04

I added offscreen drawing to OnPaint. At times I could see the individual dots being drawn Smile | :)

Other than that great control and thanks!

t

relavent code



		// OnPaint is now an override rather than an event in version 1.1

		protected override void OnPaint(PaintEventArgs e)

		{

			// create a Graphics object

			Graphics g = e.Graphics;

				

			//create our offscreen bitmap

			Bitmap b = new Bitmap(ClientRectangle.Width,

				ClientRectangle.Height);

			Graphics bg = Graphics.FromImage(b);

			bg.Clear(this.BackColor);

			

			// find the rectangle for the splitter and paint it

			Rectangle r = this.ClientRectangle; // fixed in version 1.1

//			g.FillRectangle(new SolidBrush(this.BackColor), r);

 

				#region Vertical Splitter

			// Check the docking style and create the control rectangle accordingly

			if(this.Dock == DockStyle.Left || this.Dock == DockStyle.Right)

			{

				// create a new rectangle in the vertical center of the splitter for our collapse control button

				rr = new Rectangle(r.X, (int)r.Y + ((r.Height - 115)/2), 8, 115);

				// force the width to 8px so that everything always draws correctly

				this.Width = 8;

 

				// draw the background color for our control image

				if(hot)

				{

					bg.FillRectangle(new SolidBrush(hotColor), new Rectangle(rr.X + 1, rr.Y, 6, 115));

				}

				else

				{

					bg.FillRectangle(new SolidBrush(this.BackColor), new Rectangle(rr.X + 1, rr.Y, 6, 115));

				}

 

				// draw the top & bottom lines for our control image

				bg.DrawLine(new Pen(SystemColors.ControlDark, 1), rr.X + 1, rr.Y, rr.X + rr.Width - 2, rr.Y);

				bg.DrawLine(new Pen(SystemColors.ControlDark, 1), rr.X + 1, rr.Y + rr.Height, rr.X + rr.Width - 2, rr.Y + rr.Height);

 

				if(this.Enabled)

				{

					// draw the arrows for our control image

					// the ArrowPointArray is a point array that defines an arrow shaped polygon

					bg.FillPolygon(new SolidBrush(SystemColors.ControlDarkDark), ArrowPointArray(rr.X + 2, rr.Y + 3));

					bg.FillPolygon(new SolidBrush(SystemColors.ControlDarkDark), ArrowPointArray(rr.X + 2, rr.Y + rr.Height - 9));

				}

 

				// draw the dots for our control image using a loop

				int x = rr.X + 3;

				int y = rr.Y + 14;

 

				// Visual Styles added in version 1.1

				switch(visualStyle)

				{

					case VisualStyles.Mozilla:

 

						for(int i=0; i < 30; i++)

						{

							// light dot

							bg.DrawLine(new Pen(SystemColors.ControlLightLight), x, y + (i*3), x+1, y + 1 + (i*3));

							// dark dot

							bg.DrawLine(new Pen(SystemColors.ControlDarkDark), x+1, y + 1 + (i*3), x+2, y + 2 + (i*3));

							// overdraw the background color as we actually drew 2px diagonal lines, not just dots

							if(hot)

							{

								bg.DrawLine(new Pen(hotColor), x+2, y + 1 + (i*3), x+2, y + 2 + (i*3));

							}

							else

							{

								bg.DrawLine(new Pen(this.BackColor), x+2, y + 1 + (i*3), x+2, y + 2 + (i*3));

							}

						}

						break;

 

					case VisualStyles.DoubleDots:

						for(int i=0; i < 30; i++)

						{

							// light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLightLight), x, y + 1 + (i*3), 1, 1 );

							// dark dot

							bg.DrawRectangle(new Pen(SystemColors.ControlDark), x - 1, y +(i*3), 1, 1 );

							i++;

							// light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLightLight), x + 2, y + 1 + (i*3), 1, 1 );

							// dark dot

							bg.DrawRectangle(new Pen(SystemColors.ControlDark), x + 1, y  + (i*3), 1, 1 );

						}

						break;

 

					case VisualStyles.Win9x:

 

						bg.DrawLine(new Pen(SystemColors.ControlLightLight), x, y, x + 2, y);

						bg.DrawLine(new Pen(SystemColors.ControlLightLight), x, y, x,y + 90);

						bg.DrawLine(new Pen(SystemColors.ControlDark), x + 2, y, x + 2, y + 90);

						bg.DrawLine(new Pen(SystemColors.ControlDark), x, y + 90, x + 2, y + 90);

						break;

 

					case VisualStyles.XP:

 

						for(int i=0; i < 18; i++)

						{

							// light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLight), x, y + (i*5), 2, 2 );

							// light light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLightLight), x + 1, y + 1 + (i*5), 1, 1 );

							// dark dark dot

							bg.DrawRectangle(new Pen(SystemColors.ControlDarkDark), x, y +(i*5), 1, 1 );

							// dark fill

							bg.DrawLine(new Pen(SystemColors.ControlDark), x, y + (i*5), x, y + (i*5) + 1);

							bg.DrawLine(new Pen(SystemColors.ControlDark), x, y + (i*5), x + 1, y + (i*5));

						}

						break;

 

					case VisualStyles.Lines:

 

						for(int i=0; i < 44; i++)

						{

							bg.DrawLine(new Pen(SystemColors.ControlDark), x, y + (i*2), x + 2, y + (i*2));

						}

 

						break;

				}

 

				// Added in version 1.3

				if(this.borderStyle != System.Windows.Forms.Border3DStyle.Flat)

				{

					// Paint the control border

					ControlPaint.DrawBorder3D(bg, this.ClientRectangle, this.borderStyle, Border3DSide.Left);

					ControlPaint.DrawBorder3D(bg, this.ClientRectangle, this.borderStyle, Border3DSide.Right);

				}

			}

 

				#endregion

 

				// Horizontal Splitter support added in v1.2

 

				#region Horizontal Splitter

 

			else if (this.Dock == DockStyle.Top || this.Dock == DockStyle.Bottom)

			{

				// create a new rectangle in the horizontal center of the splitter for our collapse control button

				rr = new Rectangle((int)r.X + ((r.Width - 115)/2), r.Y, 115, 8);

				// force the height to 8px

				this.Height = 8;

 

				// draw the background color for our control image

				if(hot)

				{

					bg.FillRectangle(new SolidBrush(hotColor), new Rectangle(rr.X, rr.Y + 1, 115, 6));

				}

				else

				{

					bg.FillRectangle(new SolidBrush(this.BackColor), new Rectangle(rr.X, rr.Y + 1, 115, 6));

				}

 

				// draw the left & right lines for our control image

				bg.DrawLine(new Pen(SystemColors.ControlDark, 1), rr.X, rr.Y + 1, rr.X, rr.Y + rr.Height - 2);

				bg.DrawLine(new Pen(SystemColors.ControlDark, 1), rr.X + rr.Width, rr.Y + 1, rr.X + rr.Width, rr.Y + rr.Height - 2);

 

				if(this.Enabled)

				{

					// draw the arrows for our control image

					// the ArrowPointArray is a point array that defines an arrow shaped polygon

					bg.FillPolygon(new SolidBrush(SystemColors.ControlDarkDark), ArrowPointArray(rr.X + 3, rr.Y + 2));

					bg.FillPolygon(new SolidBrush(SystemColors.ControlDarkDark), ArrowPointArray(rr.X +  rr.Width - 9, rr.Y + 2));

				}

 

				// draw the dots for our control image using a loop

				int x = rr.X + 14;

				int y = rr.Y + 3;

 

				// Visual Styles added in version 1.1

				switch(visualStyle)

				{

					case VisualStyles.Mozilla:

 

						for(int i=0; i < 30; i++)

						{

							// light dot

							bg.DrawLine(new Pen(SystemColors.ControlLightLight), x + (i*3), y, x + 1 + (i*3), y + 1);

							// dark dot

							bg.DrawLine(new Pen(SystemColors.ControlDarkDark), x + 1 + (i*3), y + 1, x + 2 + (i*3), y + 2);

							// overdraw the background color as we actually drew 2px diagonal lines, not just dots

							if(hot)

							{

								bg.DrawLine(new Pen(hotColor), x + 1 + (i*3), y + 2, x + 2 + (i*3), y + 2);

							}

							else

							{

								bg.DrawLine(new Pen(this.BackColor),  x + 1 + (i*3), y + 2, x + 2 + (i*3), y + 2);

							}

						}

						break;

 

					case VisualStyles.DoubleDots:

 

						for(int i=0; i < 30; i++)

						{

							// light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLightLight), x + 1 + (i*3), y, 1, 1 );

							// dark dot

							bg.DrawRectangle(new Pen(SystemColors.ControlDark), x + (i*3), y - 1, 1, 1 );

							i++;

							// light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLightLight), x + 1 + (i*3), y + 2, 1, 1 );

							// dark dot

							bg.DrawRectangle(new Pen(SystemColors.ControlDark), x + (i*3), y + 1, 1, 1 );

						}

						break;

 

					case VisualStyles.Win9x:

 

						bg.DrawLine(new Pen(SystemColors.ControlLightLight), x, y, x, y + 2);

						bg.DrawLine(new Pen(SystemColors.ControlLightLight), x, y, x + 88, y);

						bg.DrawLine(new Pen(SystemColors.ControlDark), x, y + 2, x + 88, y + 2);

						bg.DrawLine(new Pen(SystemColors.ControlDark), x + 88, y, x + 88, y + 2);

						break;

 

					case VisualStyles.XP:

 

						for(int i=0; i < 18; i++)

						{

							// light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLight), x + (i*5), y, 2, 2 );

							// light light dot

							bg.DrawRectangle(new Pen(SystemColors.ControlLightLight), x + 1 + (i*5), y + 1, 1, 1 );

							// dark dark dot

							bg.DrawRectangle(new Pen(SystemColors.ControlDarkDark), x +(i*5), y, 1, 1 );

							// dark fill

							bg.DrawLine(new Pen(SystemColors.ControlDark), x + (i*5), y, x + (i*5) + 1, y);

							bg.DrawLine(new Pen(SystemColors.ControlDark), x + (i*5), y, x + (i*5), y + 1);

						}

						break;

 

					case VisualStyles.Lines:

 

						for(int i=0; i < 44; i++)

						{

							bg.DrawLine(new Pen(SystemColors.ControlDark), x + (i*2), y, x + (i*2), y + 2);

						}

 

						break;

				}

 

				// Added in version 1.3

				if(this.borderStyle != System.Windows.Forms.Border3DStyle.Flat)

				{

					// Paint the control border

					ControlPaint.DrawBorder3D(bg, this.ClientRectangle, this.borderStyle, Border3DSide.Top);

					ControlPaint.DrawBorder3D(bg, this.ClientRectangle, this.borderStyle, Border3DSide.Bottom);

				}

			}

 

				#endregion

 

			else

			{

				throw new Exception("The Collapsible Splitter control cannot have the Filled or None Dockstyle property");

			}

				

 

			//push our bitmap forward to the screen

			g.DrawImage(b, 0, 0);

 

			bg.Dispose();

			b.Dispose();

 

			// dispose the Graphics object

			g.Dispose();

		}