NumericIndicator.cpp

/*
 * NumericIndicator.cpp
 */ 
 
#include "Indicators/NumericIndicator.h"
#include "Core/UI_Manager.h"
#include <string.h>
#include <stdio.h>
#include <math.h>
 
#include <stdlib.h>
 
template <class T>
void NumericIndicator<T>::calculateDisplayValue(float value)
{
    _displayValue = value;
    _unitPrefixPower = 0;
 
    if (fabs(_displayValue) < pow(10, -_numFractionalDigits))
    {
        _displayValue = 0;
        /* _unitPrefixPower is set above. */
    }
    else if (fabs(_displayValue) >= 1000)
    {
        while (fabs(_displayValue) >= 1000)
        {
            _unitPrefixPower += 3;
            _displayValue /= 1000;
        }
    }
    else if (fabs(_displayValue) < 1)
    {
        while (fabs(_displayValue) < 1)
        {
            _unitPrefixPower -= 3;
            _displayValue *= 1000;
        }
    }
 
    switch (_unitPrefixPower)
    {
        case -12: _unitPrefix = "p"; break;
        case -9: _unitPrefix = "n"; break;
        case -6: _unitPrefix = "u"; break;
        case -3: _unitPrefix = "m"; break;
        case 0: _unitPrefix = ""; break;
        case 3: _unitPrefix = "k"; break;
        case 6: _unitPrefix = "M"; break;
        case 9: _unitPrefix = "T"; break;
        default: _unitPrefix = ""; break;
    }
}
 
template <class T>
uint8_t NumericIndicator<T>::numNonFractionalDigits(T number)
{
    uint8_t digits = 0;
    //if (number < 0) digits = 1; // remove this line if '-' counts as a digit
    while (fabs(number) >= 1)
    {
        number /= 10;
        digits++;
    }
    return digits;
}
 
template <class T>
NumericIndicator<T>::NumericIndicator(T* valuePointer, const char* baseUnit, T maxValue, unsigned char numFractionalDigits, uint16_t locX, uint16_t locY, uint8_t maxStringBufferLength) : UIElement(locX, locY, UI_INDICATOR)
{
    _stringDrawBuffer = new char[maxStringBufferLength]();
    _valuePointer = valuePointer;
    _baseUnit = baseUnit;
    _unitPrefix = "";
    _maxValue = maxValue;
    _numFractionalDigits = numFractionalDigits;
    _numDigits = _numFractionalDigits + numNonFractionalDigits(maxValue);
}
 
template <class T>
void NumericIndicator<T>::Draw(bool redraw)
{
    if (Visible)
    {
        if (_lastValueDraw != *_valuePointer || redraw || !_lastDrawnVisible)
        {   
            _lastDrawnVisible = true;
            // If the Draw() is called on a object of the NumericIndicator, the Type is UI_INDICATOR
            // If the Draw() is called from an NumericControl object, the Type was set to UI_CONTROL there
            if(Type == UI_INDICATOR)
            {
                UiManager.Gfx->fillRect(LocX, LocY, Width, Height, UiManager.ColorBackground);
            }
 
            _lastValueDraw = *_valuePointer;
            calculateDisplayValue((float)_lastValueDraw);
 
            //https://stackoverflow.com/questions/5932214/printf-string-variable-length-item
            char formatStringBuffer[15];
            sprintf(formatStringBuffer, "%%0%d.%df%s%s", _numDigits + (_numFractionalDigits > 0 ? 1 : 0), max(0, _numFractionalDigits + _unitPrefixPower), _unitPrefix, _baseUnit);       // if _numFractionalDigits is 0, no decimal point is used (one character less); limit the number of factional characters to zero (no negative values)
            sprintf(_stringDrawBuffer, formatStringBuffer, fabs(_displayValue));
 
            uint16_t minus_width;
            UiManager.Gfx->getTextBounds("-", 0, 0, nullptr, nullptr, &minus_width, nullptr);
 
            UiManager.Gfx->setCursor(LocX + minus_width + 2 + UiManager.ElementMargin + UiManager.ElementPadding, LocY + Height - UiManager.ElementMargin - 2 * UiManager.ElementPadding - 1);
            UiManager.Gfx->print(_stringDrawBuffer);              // Draw value without minus sign
            if (_displayValue < 0) 
            { 
                // Draw minus sign
                UiManager.Gfx->setCursor(LocX + UiManager.ElementMargin + UiManager.ElementPadding, LocY + Height - UiManager.ElementMargin - 2 * UiManager.ElementPadding - 1);
                UiManager.Gfx->print("-"); 
            }
        }
    }
    else if(!Visible && _lastDrawnVisible)      // clear only when the Visible property changes from true to false
    {
        _lastDrawnVisible = false;
        UiManager.Gfx->fillRect(LocX, LocY, Width, Height, UiManager.ColorBackground);
    }
}
 
template <class T>
void NumericIndicator<T>::RecalculateDimensions()
{
    Height = UiManager.FontHeight + 2 * UiManager.ElementPadding + 2 * UiManager.ElementMargin;
    
    calculateDisplayValue(_maxValue);
    _unitPrefix = "m";           // make sure to set the _unitPrefix to a value != "" to take this width into account
 
    //https://stackoverflow.com/questions/5932214/printf-string-variable-length-item    
    char formatStringBuffer[15];
    sprintf(formatStringBuffer, "-%%0%d.%df%s%s", _numDigits + (_numFractionalDigits > 0 ? 1 : 0), max(0, _numFractionalDigits + _unitPrefixPower), _unitPrefix, _baseUnit);       // if _numFractionalDigits is 0, no decimal point is used (one character less); limit the number of factional characters to zero (no negative values)
    sprintf(_stringDrawBuffer, formatStringBuffer, 0.0f);      // calculate the length of a string with all zeroes ("0" is a wide characters)
 
    uint16_t minus_width;
    UiManager.Gfx->getTextBounds("-", 0, 0, nullptr, nullptr, &minus_width, nullptr);
 
    uint16_t string_width;
    UiManager.Gfx->getTextBounds(_stringDrawBuffer, 0, 0, nullptr, nullptr, &string_width, nullptr);
    Width = string_width + minus_width + 2 + 2 * UiManager.ElementPadding + 2 * UiManager.ElementMargin;
}