ledmeter.cpp Example File

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 /*
  * KAsteroids - Copyright (c) Martin R. Jones 1997
  *
  * Part of the KDE project
  */

 #include <QPainter>
 #include <QResizeEvent>
 #include <QFrame>
 #include <QColorGroup>
 #include "ledmeter.h"

 KALedMeter::KALedMeter( QWidget *parent ) : QFrame( parent )
 {
     mRange = 100;
     mCount = 20;
     mCurrentCount = 0;
     mValue = 0;
     setMinimumWidth( mCount * 2 + frameWidth() );
 }

 KALedMeter::~KALedMeter()
 {
     qDeleteAll(mCRanges);
     mCRanges.clear();
 }

 void KALedMeter::setRange( int r )
 {
     mRange = r;
     if ( mRange < 1 )
         mRange = 1;
     setValue( mValue );
     update();
 }

 void KALedMeter::setCount( int c )
 {
     mCount = c;
     if ( mCount < 1 )
         mCount = 1;
     setMinimumWidth( mCount * 2 + frameWidth() );
     calcColorRanges();
     setValue( mValue );
     update();
 }

 void KALedMeter::setValue( int v )
 {
     mValue = v;
     if ( mValue > mRange )
         mValue = mRange;
     else if ( mValue < 0 )
         mValue = 0;
     int c = ( mValue + mRange / mCount - 1 ) * mCount / mRange;
     if ( c != mCurrentCount )
     {
         mCurrentCount = c;
         update();
     }
 }

 void KALedMeter::addColorRange( int pc, const QColor &c )
 {
     ColorRange *cr = new ColorRange;
     cr->mPc = pc;
     cr->mColor = c;
     mCRanges.append( cr );
     calcColorRanges();
 }

 void KALedMeter::resizeEvent( QResizeEvent *e )
 {
     QFrame::resizeEvent( e );
     int w = ( width() - frameWidth() - 2 ) / mCount * mCount;
     w += frameWidth() + 2;
     setFrameRect( QRect( 0, 0, w, height() ) );
 }

 void KALedMeter::paintEvent(QPaintEvent *event)
 {
     QFrame::paintEvent(event);

     QRect b = contentsRect();
     QPainter p(this);

     unsigned cidx = 0;
     int ncol = mCount;
     QColor col = palette().foreground().color();

     if ( !mCRanges.isEmpty() )
     {
         col = mCRanges.at( cidx )->mColor;
         ncol = mCRanges.at( cidx )->mValue;
     }
     p.setBrush( col );
     p.setPen( col );

     int lw = b.width() / mCount;
     int lx = b.left() + 1;
     for ( int i = 0; i < mCurrentCount; i++, lx += lw )
     {
         if ( i > ncol )
         {
             if ( ++cidx < mCRanges.count() )
             {
                 col = mCRanges.at( cidx )->mColor;
                 ncol = mCRanges.at( cidx )->mValue;
                 p.setBrush( col );
                 p.setPen( col );
             }
         }

         p.drawRect( lx, b.top() + 1, lw - 1, b.height() - 2 );
     }
 }

 void KALedMeter::calcColorRanges()
 {
     int prev = 0;

     for(QList<ColorRange*>::iterator it = mCRanges.begin(); it != mCRanges.end(); it++)
     {
         ColorRange *cr = *it;
         cr->mValue = prev + cr->mPc * mCount / 100;
         prev = cr->mValue;
     }
 }