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Bar Graph Control

Shaibujan

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4.62/5 (25 votes)

26 Jan 2004

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Simple bar graph control class derived from CStatic

Introduction

Here is a simple bar graph control class derived from CStatic. It supports displaying real-time data, using any number of bars with different colors, using scale both in cm and inch, etc.

Using the code

How to add this control to your project:

Copy files GraphCtrl.h and GraphCtrl.cpp to your project directory, and add to your project.
Include GraphCtrl.h in files where you need to use this class.
Change CStatic definitions to CGraphCtrl.
Use the API described below.

int SetNumberOfBars(int num)
//Sets the number of bars you want to display. 
//If successful, it returns number of bars set, otherwise -1.

int SetBarColor(int idx, COLORREF clr)
//Sets the color for the bars.  idx is the index of the 
//bar from left to right (1,2,3..etc.)
//If successful, it returns index of the bar for which 
//the color was set, otherwise -1.

void SetUnit(int unit)
//Sets the scale to cm or inch. Send UCM for cm and UINCH for inch

void SetBarValue(int idx, int value)
//Sets the value of a bar.  idx is the index of the bar 
//for which the value to be set and 
//the parameter value is the value we have to set for it.

Example of Use

m_Graph.SetNumberOfBars(18); //Number of bars to be shown

m_Graph.SetBarColor(1,RGB(200,200,200)); 
    //Sets the color to the bar of index 1

m_Graph.SetBarValue(1,22); //Sets value to the bar of index 1

m_Graph.SetUnit(UCM);  //Sets scale to cm

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

Written By

Shaibujan

Team Leader

India

Mr. Shaibujan has got 9+ yrs of programming experience in C/C++, on various domains like Cryptography, Biometric Security, Network Security, Pattern Recognition, Image Processing, MPEG2, MPEG4, H.264, AAC etc.

Comments and Discussions

Vinod Viswanath14-Sep-12 21:06

Vinod Viswanath

14-Sep-12 21:06

My Vote Of 5

DRLaverdure18-Sep-10 9:27

18-Sep-10 9:27

Too many errors, RGB errors, Missing initializers, Missing routines.

There is a nice bar chart .Net component as well

oklook14-Aug-09 1:40

14-Aug-09 1:40

Take a look at http://www.componentxtra.com[^]

Cheers,
oklook

large number of bars?

Jared CompEng29-Apr-07 2:14

29-Apr-07 2:14

Confused | :confused:

Hi

I found that whenever i increased the number of bars to greater than 20, the graph only displayed a section of the bars (max 20 - in the rectangle).

I tried increasing the size of the rectangle, but this had the same result (ie no change)

Any help with this would be much appreciated.

ambiguous size of bar ??!!!?

mohsen nourian20-Sep-06 20:24

20-Sep-06 20:24

hi. thanx for your prrety and simple graph.
but i can't understand how to deal with size of bar? i have 4 bars. size of one of them is 1000 the next 90 next 50 next 5 .
how your class draw this ? it seems that it cant draw true.
could u plz guide me to solve this.
lots of thanx

Save to Bitmap File

varandas7918-Jun-06 3:00

18-Jun-06 3:00

<br />
CGraphCtrl.h<br />
<br />
#include <iostream><br />
#include <fstream><br />
using namespace std;

...
public:
...
void SaveBitmap(const char* filename);

CGraphCtrl.cpp

void CGraphCtrl::SaveBitmap(const char* filename)<br />
{<br />
	// get screen rectangle<br />
	RECT windowRect;<br />
	::GetWindowRect(m_hWnd, &windowRect);<br />
<br />
	// bitmap dimensions<br />
	int bitmap_dx = windowRect.right - windowRect.left;<br />
	int bitmap_dy = windowRect.bottom - windowRect.top;<br />
<br />
	// create file<br />
	ofstream file(filename, ios::binary);<br />
	if(!file) return;<br />
<br />
	// save bitmap file headers<br />
	BITMAPFILEHEADER fileHeader;<br />
	BITMAPINFOHEADER infoHeader;<br />
<br />
	fileHeader.bfType      = 0x4d42;<br />
	fileHeader.bfSize      = 0;<br />
	fileHeader.bfReserved1 = 0;<br />
	fileHeader.bfReserved2 = 0;<br />
	fileHeader.bfOffBits   = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);<br />
<br />
	infoHeader.biSize          = sizeof(infoHeader);<br />
	infoHeader.biWidth         = bitmap_dx;<br />
	infoHeader.biHeight        = bitmap_dy;<br />
	infoHeader.biPlanes        = 1;<br />
	infoHeader.biBitCount      = 24;<br />
	infoHeader.biCompression   = BI_RGB;<br />
	infoHeader.biSizeImage     = 0;<br />
	infoHeader.biXPelsPerMeter = 0;<br />
	infoHeader.biYPelsPerMeter = 0;<br />
	infoHeader.biClrUsed       = 0;<br />
	infoHeader.biClrImportant  = 0;<br />
<br />
	file.write((char*)&fileHeader, sizeof(fileHeader));<br />
	file.write((char*)&infoHeader, sizeof(infoHeader));<br />
<br />
	// dibsection information<br />
	BITMAPINFO info;<br />
	info.bmiHeader = infoHeader; <br />
<br />
	// ------------------<br />
	// THE IMPORTANT CODE<br />
	// ------------------<br />
	// create a dibsection and blit the window contents to the bitmap<br />
	HDC winDC = ::GetWindowDC(m_hWnd);<br />
	HDC memDC = CreateCompatibleDC(winDC);<br />
	BYTE* memory = 0;<br />
	HBITMAP bitmap = CreateDIBSection(winDC, &info, DIB_RGB_COLORS, (void**)&memory, 0, 0);<br />
	SelectObject(memDC, bitmap);<br />
	BitBlt(memDC, 0, 0, bitmap_dx, bitmap_dy, winDC, 0, 0, SRCCOPY);<br />
	DeleteDC(memDC);<br />
	::ReleaseDC(m_hWnd, winDC);<br />
<br />
	// save dibsection data<br />
	int bytes = (((24*bitmap_dx + 31) & (~31))/8)*bitmap_dy;<br />
	file.write((char *)memory, bytes);<br />
<br />
	DeleteObject(bitmap);<br />
}

error in line : using namespace std

mohsen nourian24-Sep-06 2:25

24-Sep-06 2:25

thank u varandas79
it was realy needed Rose | [Rose]

Rose | [Rose]

but it doesn't work or i cant work with it.
the compiler makes error on line :
using namespace std;
the error is :
error C2871: 'std' : does not exist or is not a namespace
could u please help me

-- modified at 1:48 Monday 25th September, 2006

problem with big values

Member 1916934-Apr-04 12:32

4-Apr-04 12:32

I found a problem when I used this control in a small window: The plot was wrong

suppose the following:

SetBarValue(0,10);
SetBarValue(1,100);
SetBarValue(0,30);

if the window height is smaller than bar[1]*unit then the graph output is wrong with bar[1] smaller than bar[0] and bar[2]

This is a scale problem and I corrected using the following code: (notice ++KM)

BOOL CGraphCtrl::OnEraseBkgnd(CDC* pDC)
{
int *BAR=new int[NumOfBars]; //++KM
float scale=1.0; //++KM
int i,max=0; //++KM

CRect rc;
GetClientRect (rc);
BGC = RGB(224,231,240);
int Width = rc.Width();
int Height= rc.Height();

int bx=0, by=0;

//find max value //++KM
for(i=0;i<(int)NumOfBars;i++) //++KM
max=(bar[i]>max)?bar[i]:max; //++KM

if(max>Height-offset-7) //++KM
{ //++KM
scale=(float)((float)(Height-offset-7)/(float)max); //++KM
} //++KM

for(i=0;i<(int)NumOfBars;i++) //++KM
{ //++KM
BAR[i] = (int)((float)(bar[i])*scale); //++KM
} //++KM

// KillTimer(1);
pDC->FillSolidRect(0,0,Width,Height,BGC);

pDC->FillSolidRect(offset-2,0,2,Height-(offset-2),RGB(0,0,0,));
pDC->FillSolidRect(offset,Height-offset,Width-offset,2,RGB(0,0,0,));

for(i=1;i<=(Height-offset)/(unit/2);i++)
{
if(i%2 != 0)
{
pDC->MoveTo(offset-2,(Height-offset) - i*(unit/2));
pDC->LineTo(offset-6,(Height-offset) - i*(unit/2));
}
else
{
pDC->MoveTo(offset-2,(Height-offset) - i*(unit/2));
pDC->LineTo(offset-10,(Height-offset) - i*(unit/2));
}
}

for(i=0;i<(int)NumOfBars;i++)
{
bx = ((Width-offset)/NumOfBars)*i+offset;
pDC->FillSolidRect(bx, Height-BAR[i]-offset,(Width-offset)/NumOfBars,BAR[i],BC[i]); //++KM
pDC->Draw3dRect(bx, Height-BAR[i]-offset,(Width-offset)/NumOfBars,BAR[i],RGB(255,255,255),BC[i]); //++KM
}

delete BAR; //++KM

return CStatic::OnEraseBkgnd(pDC);
}

(there is another problem with the original code: It changes the values of original data: bar[i])

Re: problem with big values

mohsen nourian24-Sep-06 19:27

24-Sep-06 19:27

thanx. u did solve my problem
u got my 5

Member 1916934-Apr-04 3:33

4-Apr-04 3:33

I can't find that function in the source!

Re: SetBarColor

hucker14-Jun-04 11:01

14-Jun-04 11:01

The source code does not match the executable. The SetBarColor method is missing. (e.g. the compiled EXE file has colored bars but the one built from source does not...)

Chuck

Re: SetBarColor

NiFF8-Dec-04 23:44

8-Dec-04 23:44

I made it, it is quite simple :

Add in .h :
/////////////////// 8< cut 8< ///////////////////
int SetBarColor(int idx, COLORREF clr);
/////////////////// 8< cut 8< ///////////////////

Add in .cpp :
/////////////////// 8< cut 8< ///////////////////
int CGraphCtrl::SetBarColor(int idx, COLORREF clr)
{
if(idx < this->NumOfBars && idx >= 0){
BC[idx] = clr;
return idx;
} else {
return -1;
}
Invalidate();
}
/////////////////// 8< cut 8< ///////////////////

Hope this helps...

Member 2545852-Mar-04 9:18

2-Mar-04 9:18

Hello author,

I am learning to write VC++ programs studying the programs given here. Came across your program, seems wonderful. May be this is 2 elementary but the program has memory leaks at two places. I hope other viewrs have spotted it and corrected it.
If not ... at the following in the destructor:
CGraphCtrl::~CGraphCtrl()
{
if(bar)
{
delete [] bar;
bar =0;
}
if(BC)
{
delete [] BC;
BC =0;
}
}

Chaitanya123

Re: - Memory Leak

Shaibujan3-Mar-04 6:07

3-Mar-04 6:07

Hi,

There is no memory leak!

We have to use
delete[] bar;
only if bar is allocated dynamically using,
bar = new int[MAXBARS];
but here the variable bar is declare as
int bar[MAXBARS]; (allocated in stack)
This memory will be cleared automatically when it exits its scope.

same with BC also.

Thanks,

Shaibu

Incorrect Device MapMode ...

Behzad Ebrahimi3-Feb-04 2:49

Behzad Ebrahimi

3-Feb-04 2:49

Hi, your graph is pretty.

But, I think your [default] Device MapeMode is incompatible by your defines:
#define UCM 28
#define UINCH 72
Because defualt MapMode is MM_TEXT.
But you designed or defined your Map by MM_TWIPS.
So call pDC->SetMapMode(MM_TWIPS) in your class to have correct ruler.

Another suggection: To have an "flicker-free" drawing, search that keyword in this site.

Thanks, BEB

Re: Incorrect Device MapMode ...

Shaibujan3-Feb-04 6:21

3-Feb-04 6:21

Dear Behzad,

Thankyou very much for the suggestions.

Shaibu

Question on OnCustomDraw

YoSilver27-Jan-04 15:17

27-Jan-04 15:17

What's the use of
void OnCustomDraw(NMHDR* pNMHDR, LRESULT* pResult);
for the static control????

Re: Question on OnCustomDraw

Shaibujan28-Jan-04 6:49

28-Jan-04 6:49

Hi,

It has nothing to do there. Smile | :)

Smile | :)

I had to delete those test code lines.

Regards,

Shaibu

Finally about time...

S^nyp27-Jan-04 12:00

S^nyp

27-Jan-04 12:00

I have been waiting for a long time for a simple bar graph control, was too lazy, thanks, you got my 5.

Actual Linux Penguins were harmed in the creation of this message.

Re: Finally about time...

Shaibujan27-Jan-04 19:27

27-Jan-04 19:27

Thanks Snyp Big Grin | :-D

Big Grin | :-D

Shaibu

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