qt5-legatus-legacy/Lts/Tools/QLedLine/qledchar.cpp

/**
  * @RDE_HEADER@
  * Implements a QLedMatrix to display a single character
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Florian Schult, SLSE, 2016-03-18
  */

#include "qledchar.h"

#include <QFontMetrics>
#include <QPainter>

#define s_fontName QStringLiteral("monospace")

QLedChar::QLedChar(int height, QWidget *parent, const QChar &letter)
  : QLedMatrix(parent)
  , m_ptHeight(findPtHeight(height))
  , m_font()
  , m_color()
  , m_bgColor(QColor(34,34,34))
  , m_image()
  , m_size()
  , m_letter(letter)
  , m_isTransparent(false)
  , m_isLetterVisible(true)
{
  init();
}

void QLedChar::init()
{
  m_font = QFont(s_fontName, m_ptHeight);
  m_font.setStyleStrategy(QFont::NoAntialias);
  QFontMetrics metrics(m_font);

  m_size.setWidth(metrics.maxWidth());
  m_size.setHeight(metrics.height());
  setSize(m_size);
}

QChar QLedChar::letter() const
{
  return m_letter;
}

QLedChar::~QLedChar()
{
}

void QLedChar::setLetter(const QChar &letter)
{
  m_letter = letter;

  if (!m_isLetterVisible)
  {
    for(int row = 0; row < m_size.height(); ++row)
    {
      for(int col = 0; col < m_size.width(); ++col)
      {
        setColorAt(row, col, NoColor);
      }
    }
    return;
  }

  QImage image(m_size,QImage::Format_RGB32);
  QPainter painter;
  painter.begin(&image);
  painter.setFont(m_font);
  painter.fillRect(image.rect(), m_bgColor);
  painter.setPen(m_color);
  painter.drawText(QPoint(0,m_ptHeight), letter);
  painter.end();

  setImage(image);
  drawImage();
}

void QLedChar::drawImage()
{
  for(int row = 0; row < m_size.height(); ++row)
  {
    for(int col = 0; col < m_size.width(); ++col)
    {
      setColorAt(row, col, m_image.pixel(col, row));
    }
  }
}

QImage QLedChar::image() const
{
  return m_image;
}

void QLedChar::setImage(const QImage &image)
{
  m_image = image;
  drawImage();
}

int QLedChar::findPtHeight(int maxPxHeight)
{
  int bestPtHeight = 0;
  // Starting difference, should be at least 0.35
  float difference = 0.4f;
  float differenceStep = difference / 2;
  bool heightFound = false;

  while(!heightFound)
  {
    differenceStep /= 2;
    float ptHeight = maxPxHeight - (maxPxHeight * difference);

    QFont font(s_fontName,ptHeight);
    QFontMetrics metrics(font);

    int pxHeight = metrics.height();

    if(pxHeight < maxPxHeight)
      difference -= differenceStep;
    else if(pxHeight > maxPxHeight)
      difference += differenceStep;
    else
    {
      bestPtHeight = ptHeight;
      heightFound = true;
    }

    if(differenceStep == 0)
    {
      // Catches invalid pixelsizes, which lack proper pointsizes
      bestPtHeight = ptHeight-1;
      heightFound = true;
    }
  }
  return bestPtHeight;
}

QSize QLedChar::charSize() const
{
  return m_size;
}

void QLedChar::setLetterVisible(bool visible)
{
  m_isLetterVisible = visible;
  setLetter(m_letter);
}

bool QLedChar::isTransparent() const
{
  return m_isTransparent;
}

void QLedChar::setTransparent(bool isTransparent)
{
  m_isTransparent = isTransparent;
  if (isTransparent)
    setBackgroundMode(Qt::TransparentMode);
  else
    setBackgroundMode(Qt::OpaqueMode);
}

bool QLedChar::letterVisible() const
{
  return m_isLetterVisible;
}

void QLedChar::setCharHeight(int height)
{
  m_ptHeight = findPtHeight(height);
  init();
}

int QLedChar::charHeight() const
{
  return m_size.height();
}

QColor QLedChar::color() const
{
  return m_color;
}

void QLedChar::setColor(const QColor &color)
{
  m_color = color;
  setLetter(m_letter);
}

QColor QLedChar::bgColor() const
{
  return m_bgColor;
}

void QLedChar::setBgColor(const QColor &bgColor)
{
  m_bgColor = bgColor;
  setLetter(m_letter);
}

void QLedChar::onFlashTimerTimeout()
{
  m_isLetterVisible = !m_isLetterVisible;
  setLetter(m_letter);
}