shapespiechartcontainer.cpp

来自「series60 应用程序开发的源代码 series60 应用程序开发的源代码」· C++ 代码 · 共 177 行

/**
 * 
 * @brief Definition of CShapesBarChartContainer
 *
 * Copyright (c) EMCC Software Ltd 2003
 * @version 1.0
 */

// INCLUDE FILES

// Class includes
#include "ShapesPieChartContainer.h"

// System includes
#include <e32math.h>    // KPi and Math:: trigonometric functions
#include <eikenv.h>        // AKN_LAF_COLOR()

// User includes
#include "ShapesModel.h"    // CShapesModel

// CONSTANTS

#define KPieRect TRect(TPoint(40, 40), TPoint(120, 120))

const TInt KStartPointX = 0; 
const TInt KStartPointY = 70;
const TInt KMaxColorValue = 215;

// ================= MEMBER FUNCTIONS =======================

/**
 * Symbian OS 2 phase constructor.
 * Constructs the CShapesPieChartContainer using the NewLC method, popping
 * the constructed object from the CleanupStack before returning it.
 * 
 * @param aShapesModel a reference to the model
 * @param aRect The rectangle for this window
 * @return The newly constructed CShapesPieChartContainer
 */
CShapesPieChartContainer* CShapesPieChartContainer::NewL(CShapesModel& aShapesModel, const TRect& aRect)
{
    CShapesPieChartContainer* self = CShapesPieChartContainer::NewLC(aShapesModel, aRect);
    CleanupStack::Pop(self);
    return self;
}

/**
 * Symbian OS 2 phase constructor.
 * Constructs the CShapesPieChartContainer using the constructor and ConstructL 
 * method, leaving the constructed object on the CleanupStack before returning it.
 * 
 * @param aShapesModel a reference to the model
 * @param aRect The rectangle for this window
 * @return The newly constructed CShapesPieChartContainer
 */
CShapesPieChartContainer* CShapesPieChartContainer::NewLC(CShapesModel& aShapesModel,  const TRect& aRect)
{
    CShapesPieChartContainer* self = new (ELeave) CShapesPieChartContainer(aShapesModel);
    CleanupStack::PushL(self);
    self->ConstructL(aRect);
    return self;
}

/**
 * C++ constructor
 *
 * @param aShapesModel a reference to the model
 */
CShapesPieChartContainer::CShapesPieChartContainer(CShapesModel& aShapesModel)
 : iShapesModel(aShapesModel)
{
}

/**
 * Symbian OS 2nd phase constructor.  Creates a Window for the control to draw to.
 * Activates the control
 *
 * @param aRect The rectangle for this window
 */ 
void CShapesPieChartContainer::ConstructL(const TRect& aRect)
{
    CreateWindowL();
    SetRect(aRect);
    ActivateL();
}

/**
 * Destructor
 */
CShapesPieChartContainer::~CShapesPieChartContainer()
{
}

/**
 * Draw function calls DrawPie()
 *
 * @param aRect The rectangle to draw to (not used)
 */
void CShapesPieChartContainer::Draw(const TRect& /*aRect*/) const
{
    DrawPie();    
}

/**
 * Draws the pie chart using the GC DrawPie() function
 * Trigonometrical rotation functions are used to calculate correct
 * radials for each pie segment
 */
void CShapesPieChartContainer::DrawPie() const
{
    // Clear the graphics context.
    CWindowGc& gc = SystemGc();    
    gc.Clear();
    
    // Set up variables necessary for calculations
    const TPoint centerOfPie(KPieRect.Center());

    TPoint startPoint(KStartPointX, KStartPointY);    // cartesian based coordinate system
    TPoint endPoint(startPoint);                    // cartesian based coordinate system

    // Set up the random seed.
    TTime time;
    time.HomeTime();
    TInt64 colorSeed = time.Int64();

    const TReal sumOfData = iShapesModel.SumOfElements();    // TReal for floating-point division.
    const TInt numElements = iShapesModel.NumElements();

    for (TInt i = 0; i < numElements; i++)
    {
        // Obtain a value from the model
        TInt currentVal = iShapesModel.ElementAt(i);
    
        if (currentVal)
        {
            // Generate a random color and set brush parameters - note that this will result in
            // different colors being used each time this view is selected (even for the same data).
            TInt randomColor = Math::Rand(colorSeed);

            randomColor = randomColor % KMaxColorValue;        
            TRgb brushColor = AKN_LAF_COLOR(randomColor);

            gc.SetBrushColor(brushColor);
            gc.SetBrushStyle(CGraphicsContext::EForwardDiagonalHatchBrush);
        
            // Make the start of the new pie slice the end of the last one
            startPoint = endPoint;

            // Calculate the end point for the new pie segment based on rotation equations
            
            // Calculate the angle as a percentage of the data.
            const TReal angleInRadians = (currentVal * (2 * KPi)) / sumOfData;

            // Calculate the sine and cosine of the angle.
            TReal trigResultCos;
            Math::Cos(trigResultCos, angleInRadians);

            TReal trigResultSin;
            Math::Sin(trigResultSin, angleInRadians);

            // Calculate end point cartesian coordinates, casting results back to integers.
            const TInt newX = (TInt)((startPoint.iX * trigResultCos) - (startPoint.iY * trigResultSin)); 
            const TInt newY = (TInt)((startPoint.iX * trigResultSin) + (startPoint.iY * trigResultCos));
            endPoint.SetXY(newX, newY);
        
            // Adjust from Cartesian to screen coordinates
            const TPoint pieStartPoint(centerOfPie.iX + startPoint.iX, centerOfPie.iY - startPoint.iY);
            const TPoint pieEndPoint(centerOfPie.iX + endPoint.iX, centerOfPie.iY - endPoint.iY);
        
            // Draw the pie
            gc.DrawPie(KPieRect, pieStartPoint, pieEndPoint);
        }
    }
}
    
// End of File