Categories: How To | Debugging

This page was last modified 08:33, 29 June 2007.

From Forum Nokia Wiki

This simple control allows you to monitor available RAM in your mobile. To use it, just instantiate the control and set a timer to periodically invoke the plot function:

// The view owns the RAM control
void CSystemView::CmdStartTimers()
{
    iRAMControl->Reset();
    DrawDeferred();
 
    const TInt KUpdateInterval = 1000000;   // 1 sec
    iUpdateTimer->Start(KUpdateInterval, KUpdateInterval, TCallBack(DoUpdateL, this));
}
 
TInt CSystemView::DoUpdateL(TAny* aPtr)
{
    CSystemView* self = static_cast<CSystemView*>(aPtr);
    self->iRAMControl->PlotL();
 
    return 0;
}

The RAM monitor control class:

#include <coecntrl.h>   // CCoeControl
 
class CRAMControl : public CCoeControl
{
public:
    void ConstructL(const TRect& aRect, const CCoeControl* aParent);
    ~CRAMControl();
 
    void Reset();
    void PlotL();
 
private:
    void Draw(const TRect& aRect) const;
    void SizeChanged();
 
private:
    CArrayFix<TInt>* iFreeRAMList;
    TInt iFreeRAM;
    TReal32 iTotalRAM;
 
    CArrayFix<TPoint>* iPointList;
    TRect iPaintRect;
 
    HBufC* iFreeRAMText;
};

#include "RAMControl.h"
#include <YourApp.rsg>  // Define r_text_free_ram, etc
 
#include <coemain.h>    // CCoeEnv
#include <eikenv.h>     // CEikonEnv
#include <hal.h>
 
void CRAMControl::ConstructL(const TRect& aRect, const CCoeControl* aParent)
{
    if (aParent == 0)
        CreateWindowL();
    else
        SetContainerWindowL(*aParent);
 
    iFreeRAMList = new(ELeave) CArrayFixSeg<TInt>(5);
    iPointList = new(ELeave) CArrayFixFlat<TPoint>(5);
 
    iFreeRAMText = iCoeEnv->AllocReadResourceL(R_TEXT_FREE_RAM);
 
    SetRect(aRect);
    ActivateL();
}
 
CRAMControl::~CRAMControl()
{
    delete iFreeRAMText;
 
    delete iPointList;
    delete iFreeRAMList;
}
 
void CRAMControl::Reset()
{
    iFreeRAMList->Reset();
    iTotalRAM = 0;
 
    iPointList->Reset();
}
 
void CRAMControl::Draw(const TRect& /*aRect*/) const
{
    CWindowGc& gc = SystemGc();
 
    gc.Clear(iPaintRect);
    gc.SetClippingRect(iPaintRect);
    gc.SetPenColor(KRgbRed);
    gc.DrawPolyLine(iPointList);
 
    gc.SetPenColor(KRgbBlack);
    gc.DrawRect(iPaintRect);
 
    const CFont* font = iEikonEnv->LegendFont();
    gc.UseFont(font);
 
    TInt freeRam = 0;
    HAL::Get(HAL::EMemoryRAMFree, freeRam);
    TBuf<64> freeRAMText;
    freeRAMText.Format(*iFreeRAMText, freeRam >> 10);
 
    gc.DrawText(freeRAMText, iPaintRect, iPaintRect.Height() - 
font->DescentInPixels(), CGraphicsContext::ERight);
    gc.DiscardFont();
}
 
void CRAMControl::SizeChanged()
{
    iPaintRect = Rect();
    iPaintRect.Shrink(5, 5);
}
 
void CRAMControl::PlotL()
{
    HAL::Get(HAL::EMemoryRAMFree, iFreeRAM);
 
// In case there's a new maximum of free memory, resize graphic
    TInt possibleMax = static_cast<TInt> (iFreeRAM * 1.2);
    if (possibleMax > iTotalRAM)
        iTotalRAM = possibleMax;
 
    if (iFreeRAMList->Count() == iPaintRect.Width() - 2)
        iFreeRAMList->Delete(0);
    iFreeRAMList->AppendL(iFreeRAM);
 
    iPointList->Reset();
    for (TInt i = 0; i < iFreeRAMList->Count(); ++i)
    {
        TInt x = iPaintRect.iBr.iX - 1 - iFreeRAMList->Count() + i;
    	TInt y = iPaintRect.iBr.iY - 1 - 
static_cast<TInt> (iPaintRect.Height() * (iFreeRAMList->At(i) / iTotalRAM));
        iPointList->AppendL(TPoint(x, y));
    }
	
    DrawDeferred();
}

You can check TaskSpy source code to see how this works.