/** ****************************************************************************** * * @file pfdgadgetwidget.cpp * @author Edouard Lafargue Copyright (C) 2010. * @brief * @see The GNU Public License (GPL) Version 3 * @defgroup pfdplugin * @{ * *****************************************************************************/ /* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "pfdgadgetwidget.h" #include #include #include PFDGadgetWidget::PFDGadgetWidget(QWidget *parent) : QGraphicsView(parent) { // TODO: create a proper "needle" object instead of hardcoding all this // which is ugly (but easy). setMinimumSize(64,64); setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::MinimumExpanding); setScene(new QGraphicsScene(this)); setRenderHints(QPainter::Antialiasing); m_renderer = new QSvgRenderer(); attitudeObj = NULL; headingObj = NULL; compassBandWidth = 0; /* obj2 = NULL; obj3 = NULL; */ // This timer mechanism makes needles rotate smoothly connect(&dialTimer, SIGNAL(timeout()), this, SLOT(moveNeedles())); dialTimer.start(20); /* connect(&dialTimer2,SIGNAL(timeout()), this, SLOT(moveVerticalScales())); dialTimer2.start(20); */ } PFDGadgetWidget::~PFDGadgetWidget() { // Do nothing } /*! \brief Connects the widget to the relevant UAVObjects We want: AttitudeActual, FlightBattery, Location */ void PFDGadgetWidget::connectNeedles() { if (attitudeObj != NULL) disconnect(attitudeObj,SIGNAL(objectUpdated(UAVObject*)),this,SLOT(updateAttitude(UAVObject*))); if (headingObj != NULL) disconnect(headingObj,SIGNAL(objectUpdated(UAVObject*)),this,SLOT(updateHeading(UAVObject*))); ExtensionSystem::PluginManager *pm = ExtensionSystem::PluginManager::instance(); UAVObjectManager *objManager = pm->getObject(); attitudeObj = dynamic_cast(objManager->getObject("AttitudeActual")); if (attitudeObj != NULL ) { connect(attitudeObj, SIGNAL(objectUpdated(UAVObject*)), this, SLOT(updateAttitude(UAVObject*))); } else { std::cout << "Error: Object is unknown (AttitudeActual)." << std::endl; } headingObj = dynamic_cast(objManager->getObject("PositionActual")); if (headingObj != NULL ) { connect(headingObj, SIGNAL(objectUpdated(UAVObject*)), this, SLOT(updateHeading(UAVObject*))); } else { std::cout << "Error: Object is unknown (PositionActual)." << std::endl; } gcsTelemetryObj = dynamic_cast(objManager->getObject("GCSTelemetryStats")); if (gcsTelemetryObj != NULL ) { connect(gcsTelemetryObj, SIGNAL(objectUpdated(UAVObject*)), this, SLOT(updateLinkStatus(UAVObject*))); } else { std::cout << "Error: Object is unknown (GCSTelemetryStats)." << std::endl; } } /*! \brief Updates the link stats */ void PFDGadgetWidget::updateLinkStatus(UAVObject *object1) { // Double check that the field exists: QString st = QString("Status"); QString tdr = QString("TxDataRate"); QString rdr = QString("RxDataRate"); UAVObjectField* field = object1->getField(st); UAVObjectField* field2 = object1->getField(tdr); UAVObjectField* field3 = object1->getField(rdr); if (field && field2 && field3) { QString s = field->getValue().toString(); if (m_renderer->elementExists("gcstelemetry-" + s)) { gcsTelemetryArrow->setElementId("gcstelemetry-" + s); } else { // Safeguard gcsTelemetryArrow->setElementId("gcstelemetry-Disconnected"); } } else { std::cout << "UpdateLinkStatus: Wrong field, maybe an issue with object disconnection ?" << std::endl; } } /*! \brief Reads the updated attitude and computes the new display position */ void PFDGadgetWidget::updateAttitude(UAVObject *object1) { // Double check that the field exists: QString roll = QString("Roll"); QString pitch = QString("Pitch"); UAVObjectField* field = object1->getField(roll); UAVObjectField* field2 = object1->getField(pitch); if (field && field2) { // These factors assume some things about the PFD SVG, namely: // - Roll value in degrees // - Pitch lines are 300px high for a +20/-20 range, which means // 7.5 pixels per pitch degree. rollTarget = field->getDouble()*(-1); pitchTarget = field2->getDouble()*7.5; if (!dialTimer.isActive()) dialTimer.start(); // Rearm the dial Timer which might be stopped. } else { std::cout << "UpdateAttitude: Wrong field, maybe an issue with object disconnection ?" << std::endl; } } /*! \brief Updates the compass reading and speed dial. This also updates speed & altitude according to GPS data. Note: the speed dial shows the ground speed at the moment, because there is no airspeed by default. Should become configurable in a future gadget release (TODO) */ void PFDGadgetWidget::updateHeading(UAVObject *object1) { // Double check that the field exists: QString fieldname = QString("Heading"); UAVObjectField* field = object1->getField(fieldname); if (field) { // These factors assume some things about the PFD SVG, namely: // - Heading value in degrees // - Scale is 540 degrees large headingTarget = field->getDouble()*compassBandWidth/(-540); } else { std::cout << "UpdateHeading: Wrong field, maybe an issue with object disconnection ?" << std::endl; } fieldname = QString("Groundspeed"); field = object1->getField(fieldname); if (field) { // The speed scale represents 30km/h (6 * 5) // 3.6 : convert m/s to km/h double val = field->getDouble(); groundspeedTarget = 3.6*val*speedScaleHeight/(30); } fieldname = QString("Altitude"); field = object1->getField(fieldname); if (field) { // The altitude scale represents 30 meters altitudeTarget = field->getDouble()*altitudeScaleHeight/(30); } if (!dialTimer.isActive()) dialTimer.start(); // Rearm the dial Timer which might be stopped. } /*! \brief Called by the UAVObject which got updated */ void PFDGadgetWidget::updateAirspeed(UAVObject *object3) { } /*! \brief Called by the UAVObject which got updated */ void PFDGadgetWidget::updateAltitude(UAVObject *object3) { } /*! \brief Called by the UAVObject which got updated */ void PFDGadgetWidget::updateBattery(UAVObject *object3) { } /*! \brief Sets up the PFD from the SVG master file. Initializes the display, and does all the one-time calculations. */ void PFDGadgetWidget::setDialFile(QString dfn) { if (QFile::exists(dfn)) { m_renderer->load(dfn); if(m_renderer->isValid()) { /* The PFD element IDs are fixed, not like with the analog dial. - Background: background - Foreground: foreground (contains all fixed elements, including plane) - earth/sky : world - Roll scale: rollscale - compass frame: compass (part of the foreground) - compass band : compass-band - Home point: homewaypoint - Next point: nextwaypoint - Home point bearing: homewaypoint-bearing - Next point bearing: nextwaypoint-bearing - Speed rectangle (left side): speed-bg - Speed scale: speed-scale. - Black speed window: speed-window. - Altitude rectangle (right site): altitude-bg. - Altitude scale: altitude-scale. - Black altitude window: altitude-window. - GCS Telemetry status arrow: gcstelemetry-XXXX */ QGraphicsScene *l_scene = scene(); l_scene->clear(); // Deletes all items contained in the scene as well. m_background = new QGraphicsSvgItem(); // All other items will be clipped to the shape of the background m_background->setFlags(QGraphicsItem::ItemClipsChildrenToShape| QGraphicsItem::ItemClipsToShape); m_background->setSharedRenderer(m_renderer); m_background->setElementId("background"); l_scene->addItem(m_background); m_world = new QGraphicsSvgItem(); m_world->setParentItem(m_background); m_world->setSharedRenderer(m_renderer); m_world->setElementId("world"); l_scene->addItem(m_world); // red Roll scale: rollscale m_rollscale = new QGraphicsSvgItem(); m_rollscale->setSharedRenderer(m_renderer); m_rollscale->setElementId("rollscale"); l_scene->addItem(m_rollscale); // Home point: m_homewaypoint = new QGraphicsSvgItem(); // Next point: m_nextwaypoint = new QGraphicsSvgItem(); // Home point bearing: m_homepointbearing = new QGraphicsSvgItem(); // Next point bearing: m_nextpointbearing = new QGraphicsSvgItem(); QGraphicsSvgItem *m_foreground = new QGraphicsSvgItem(); m_foreground->setParentItem(m_background); m_foreground->setSharedRenderer(m_renderer); m_foreground->setElementId("foreground"); l_scene->addItem(m_foreground); //////////////////// // Compass //////////////////// // Get the default location of the Compass: QMatrix compassMatrix = m_renderer->matrixForElement("compass"); qreal startX = compassMatrix.mapRect(m_renderer->boundsOnElement("compass")).x(); qreal startY = compassMatrix.mapRect(m_renderer->boundsOnElement("compass")).y(); // Then once we have the initial location, we can put it // into a QGraphicsSvgItem which we will display at the same // place: we do this so that the heading scale can be clipped to // the compass dial region. m_compass = new QGraphicsSvgItem(); m_compass->setSharedRenderer(m_renderer); m_compass->setElementId("compass"); m_compass->setFlags(QGraphicsItem::ItemClipsChildrenToShape| QGraphicsItem::ItemClipsToShape); l_scene->addItem(m_compass); QTransform matrix; matrix.translate(startX,startY); m_compass->setTransform(matrix,false); // Now place the compass scale inside: m_compassband = new QGraphicsSvgItem(); m_compassband->setSharedRenderer(m_renderer); m_compassband->setElementId("compass-band"); m_compassband->setParentItem(m_compass); l_scene->addItem(m_compassband); matrix.reset(); // Note: the compass band has to be a path, which means all text elements have to be // converted, ortherwise boundsOnElement does not compute the height correctly // if the highest element is a text element. This is a Qt Bug as far as I can tell. // compass-scale is the while bottom line inside the band: using the band's width // includes half the width of the letters, which causes errors: compassBandWidth = m_renderer->boundsOnElement("compass-scale").width(); //////////////////// // Speed //////////////////// // Speedometer on the left hand: // compassMatrix = m_renderer->matrixForElement("speed-bg"); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("speed-bg")).x(); startY = compassMatrix.mapRect(m_renderer->boundsOnElement("speed-bg")).y(); QGraphicsSvgItem *verticalbg = new QGraphicsSvgItem(); verticalbg->setSharedRenderer(m_renderer); verticalbg->setElementId("speed-bg"); verticalbg->setFlags(QGraphicsItem::ItemClipsChildrenToShape| QGraphicsItem::ItemClipsToShape); l_scene->addItem(verticalbg); matrix.reset(); matrix.translate(startX,startY); verticalbg->setTransform(matrix,false); // Note: speed-scale should contain exactly 6 major ticks // for 30km/h m_speedscale = new QGraphicsItemGroup(); m_speedscale->setParentItem(verticalbg); QGraphicsSvgItem *speedscalelines = new QGraphicsSvgItem(); speedscalelines->setSharedRenderer(m_renderer); speedscalelines->setElementId("speed-scale"); speedScaleHeight = m_renderer->matrixForElement("speed-scale").mapRect( m_renderer->boundsOnElement("speed-scale")).height(); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("speed-bg")).width(); startX -= m_renderer->matrixForElement("speed-scale").mapRect( m_renderer->boundsOnElement("speed-scale")).width(); //speedscalelines->setParentItem(verticalbg); matrix.reset(); matrix.translate(startX,0); speedscalelines->setTransform(matrix,false); // Quick way to reposition the item before putting it in the group: speedscalelines->setParentItem(verticalbg); m_speedscale->addToGroup(speedscalelines); // (reparents the item) // Add the scale text elements: QGraphicsTextItem *speed0 = new QGraphicsTextItem("0"); speed0->setDefaultTextColor(QColor("White")); speed0->setFont(QFont("Arial",(int) speedScaleHeight/30)); matrix.reset(); matrix.translate(compassMatrix.mapRect(m_renderer->boundsOnElement("speed-bg")).width()/10,-speedScaleHeight/30); speed0->setTransform(matrix,false); speed0->setParentItem(verticalbg); m_speedscale->addToGroup(speed0); for (int i=0; i<6;i++) { speed0 = new QGraphicsTextItem(""); speed0->setDefaultTextColor(QColor("White")); speed0->setFont(QFont("Arial",(int) speedScaleHeight/30)); speed0->setPlainText(QString().setNum(i*5+1)); matrix.translate(0,speedScaleHeight/6); speed0->setTransform(matrix,false); speed0->setParentItem(verticalbg); m_speedscale->addToGroup(speed0); } // Now vertically center the speed scale on the speed background QRectF rectB = verticalbg->boundingRect(); QRectF rectN = speedscalelines->boundingRect(); m_speedscale->setPos(0,rectB.height()/2-rectN.height()/2-rectN.height()/6); // Isolate the speed window and put it above the speed scale compassMatrix = m_renderer->matrixForElement("speed-window"); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("speed-window")).x(); startY = compassMatrix.mapRect(m_renderer->boundsOnElement("speed-window")).y(); qreal speedWindowHeight = compassMatrix.mapRect(m_renderer->boundsOnElement("speed-window")).height(); QGraphicsSvgItem *speedwindow = new QGraphicsSvgItem(); speedwindow->setSharedRenderer(m_renderer); speedwindow->setElementId("speed-window"); speedwindow->setFlags(QGraphicsItem::ItemClipsChildrenToShape| QGraphicsItem::ItemClipsToShape); l_scene->addItem(speedwindow); matrix.reset(); matrix.translate(startX,startY); speedwindow->setTransform(matrix,false); // Last create a Text Item at the location of the speed window // and save it for future updates: m_speedtext = new QGraphicsTextItem("0000"); m_speedtext->setDefaultTextColor(QColor("White")); m_speedtext->setFont(QFont("Arial",(int) speedWindowHeight/2)); matrix.reset(); m_speedtext->setParentItem(speedwindow); //////////////////// // Altitude //////////////////// // Right hand, very similar to speed compassMatrix = m_renderer->matrixForElement("altitude-bg"); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("altitude-bg")).x(); startY = compassMatrix.mapRect(m_renderer->boundsOnElement("altitude-bg")).y(); verticalbg = new QGraphicsSvgItem(); verticalbg->setSharedRenderer(m_renderer); verticalbg->setElementId("altitude-bg"); verticalbg->setFlags(QGraphicsItem::ItemClipsChildrenToShape| QGraphicsItem::ItemClipsToShape); l_scene->addItem(verticalbg); matrix.reset(); matrix.translate(startX,startY); verticalbg->setTransform(matrix,false); // Note: altitude-scale should contain exactly 6 major ticks // for 30 meters m_altitudescale = new QGraphicsItemGroup(); m_altitudescale->setParentItem(verticalbg); QGraphicsSvgItem *altitudescalelines = new QGraphicsSvgItem(); altitudescalelines->setSharedRenderer(m_renderer); altitudescalelines->setElementId("altitude-scale"); altitudeScaleHeight = m_renderer->matrixForElement("altitude-scale").mapRect( m_renderer->boundsOnElement("altitude-scale")).height(); // Quick way to reposition the item before putting it in the group: altitudescalelines->setParentItem(verticalbg); m_altitudescale->addToGroup(altitudescalelines); // (reparents the item) // Add the scale text elements: speed0 = new QGraphicsTextItem("XXXX"); speed0->setDefaultTextColor(QColor("White")); speed0->setFont(QFont("Arial",(int) altitudeScaleHeight/30)); matrix.reset(); matrix.translate(m_renderer->matrixForElement("altitude-scale").mapRect(m_renderer->boundsOnElement("altitude-scale")).width() + m_renderer->matrixForElement("altitude-bg").mapRect(m_renderer->boundsOnElement("altitude-bg")).width()/10,-altitudeScaleHeight/30); speed0->setTransform(matrix,false); speed0->setParentItem(verticalbg); m_altitudescale->addToGroup(speed0); for (int i=0; i<6;i++) { speed0 = new QGraphicsTextItem("XXXX"); speed0->setDefaultTextColor(QColor("White")); speed0->setFont(QFont("Arial",(int) altitudeScaleHeight/30)); speed0->setPlainText(QString().setNum(i*5+1)); matrix.translate(0,altitudeScaleHeight/6); speed0->setTransform(matrix,false); speed0->setParentItem(verticalbg); m_altitudescale->addToGroup(speed0); } // Now vertically center the speed scale on the speed background rectB = verticalbg->boundingRect(); rectN = altitudescalelines->boundingRect(); m_altitudescale->setPos(0,rectB.height()/2-rectN.height()/2-rectN.height()/6); // Isolate the Altitude window and put it above the altitude scale compassMatrix = m_renderer->matrixForElement("altitude-window"); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("altitude-window")).x(); startY = compassMatrix.mapRect(m_renderer->boundsOnElement("altitude-window")).y(); qreal altitudeWindowHeight = compassMatrix.mapRect(m_renderer->boundsOnElement("altitude-window")).height(); QGraphicsSvgItem *altitudewindow = new QGraphicsSvgItem(); altitudewindow->setSharedRenderer(m_renderer); altitudewindow->setElementId("altitude-window"); altitudewindow->setFlags(QGraphicsItem::ItemClipsChildrenToShape| QGraphicsItem::ItemClipsToShape); l_scene->addItem(altitudewindow); matrix.reset(); matrix.translate(startX,startY); altitudewindow->setTransform(matrix,false); // Last create a Text Item at the location of the speed window // and save it for future updates: m_altitudetext = new QGraphicsTextItem("0000"); m_altitudetext->setDefaultTextColor(QColor("White")); m_altitudetext->setFont(QFont("Arial",(int) altitudeWindowHeight/2)); m_altitudetext->setParentItem(altitudewindow); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("altitude-window")).width()/10; matrix.reset(); matrix.translate(startX,0); m_altitudetext->setTransform(matrix,false); //////////////// // GCS Telemetry Indicator //////////////// compassMatrix = m_renderer->matrixForElement("gcstelemetry-Disconnected"); startX = compassMatrix.mapRect(m_renderer->boundsOnElement("gcstelemetry-Disconnected")).x(); startY = compassMatrix.mapRect(m_renderer->boundsOnElement("gcstelemetry-Disconnected")).y(); gcsTelemetryArrow = new QGraphicsSvgItem(); gcsTelemetryArrow->setSharedRenderer(m_renderer); gcsTelemetryArrow->setElementId("gcstelemetry-Disconnected"); l_scene->addItem(gcsTelemetryArrow); matrix.reset(); matrix.translate(startX,startY); gcsTelemetryArrow->setTransform(matrix,false); l_scene->setSceneRect(m_background->boundingRect()); ///////////////// // Item placement ///////////////// // Now Initialize the center for all transforms of the relevant elements to the // center of the background: // 1) Move the center of the needle to the center of the background. rectB = m_background->boundingRect(); rectN = m_world->boundingRect(); m_world->setPos(rectB.width()/2-rectN.width()/2,rectB.height()/2-rectN.height()/2); // 2) Put the transform origin point of the needle at its center. m_world->setTransformOriginPoint(rectN.width()/2,rectN.height()/2); rectN = m_rollscale->boundingRect(); m_rollscale->setPos(rectB.width()/2-rectN.width()/2,rectB.height()/2-rectN.height()/2); m_rollscale->setTransformOriginPoint(rectN.width()/2,rectN.height()/2); // Also to the same init for the compass: rectB = m_compass->boundingRect(); rectN = m_compassband->boundingRect(); m_compassband->setPos(rectB.width()/2-rectN.width()/2,rectB.height()/2-rectN.height()/2); m_compassband->setTransformOriginPoint(rectN.width()/2,rectN.height()/2); // Last: we just loaded the dial file which is by default valid for a "zero" value // of the needles, so we have to reset the needles too upon dial file loading, otherwise // we would end up with an offset when we change a dial file and the needle value // is not zero at that time. rollValue = 0; pitchValue = 0; headingValue = 0; groundspeedValue = 0; altitudeValue = 0; if (!dialTimer.isActive()) dialTimer.start(); // Rearm the dial Timer which might be stopped. } } else { std::cout<<"no file: "<isValid()) { std::cout<<"Dial file not loaded, not rendering"< 5)) { rollDiff =(rollTarget - rollValue)/5; } else { rollDiff = rollTarget - rollValue; dialCount--; } m_world->setRotation(m_world->rotation()+rollDiff); m_rollscale->setRotation(m_rollscale->rotation()+rollDiff); rollValue += rollDiff; ////// // Pitch ////// double pitchDiff; if ((abs((pitchValue-pitchTarget)*10) > 5)) { pitchDiff = (pitchTarget - pitchValue)/5; } else { pitchDiff = pitchTarget - pitchValue; dialCount--; } QPointF opd = QPointF(0,pitchDiff); m_world->setTransform(QTransform::fromTranslate(opd.x(),opd.y()), true); QPointF oop = m_world->transformOriginPoint(); m_world->setTransformOriginPoint((oop.x()-opd.x()),(oop.y()-opd.y())); pitchValue += pitchDiff; ////// // Heading ////// double headingOffset = 0; double headingDiff; if ((abs((headingValue-headingTarget)*10) > 5)) { headingDiff = (headingTarget - headingValue)/5; } else { headingDiff = headingTarget-headingValue; dialCount--; } double threshold = -180*compassBandWidth/540; // Note: rendering can jump oh so very slightly when crossing the 180 degree // boundary, should not impact actual useability of the display. if ((headingValue < threshold) && ((headingValue+headingDiff)>=threshold)) { // We went over 180�: activate a -360 degree offset headingOffset = 2*threshold; } else if ((headingValue >= threshold) && ((headingValue+headingDiff)setTransform(QTransform::fromTranslate(opd.x(),opd.y()), true); headingValue += headingDiff; ////// // Speed ////// if (abs(groundspeedValue-groundspeedTarget) > speedScaleHeight/120) { groundspeedValue += (groundspeedTarget-groundspeedValue)/5; } else { groundspeedValue = groundspeedTarget; dialCount--; } qreal x = m_speedscale->transform().dx(); //opd = QPointF(x,fmod(groundspeedValue,speedScaleHeight/6)); // fmod does rounding errors!! the formula below works better: opd = QPointF(x,groundspeedValue-floor(groundspeedValue/speedScaleHeight*6)*speedScaleHeight/6); m_speedscale->setTransform(QTransform::fromTranslate(opd.x(),opd.y()), false); double speedText = groundspeedValue/speedScaleHeight*30; QString s = QString().sprintf("%.0f",speedText); m_speedtext->setPlainText(s); // TODO: optimize this by skipping if not necessary... // Now update the text elements inside the scale: // (Qt documentation states that the list has the same order // as the item add order in the QGraphicsItemGroup) QList textList = m_speedscale->childItems(); qreal val = 5*floor(groundspeedValue/speedScaleHeight*6)+20; foreach( QGraphicsItem * item, textList) { if (QGraphicsTextItem *text = qgraphicsitem_cast(item)) { QString s = (val<0) ? QString() : QString().sprintf("%.0f",val); text->setPlainText(s); val -= 5; } } ////// // Altitude ////// if (abs(altitudeValue-altitudeTarget) > altitudeScaleHeight/120) { altitudeValue += (altitudeTarget-altitudeValue)/5; } else { altitudeValue = altitudeTarget; dialCount--; } x = m_altitudescale->transform().dx(); //opd = QPointF(x,fmod(altitudeValue,altitudeScaleHeight/6)); // fmod does rounding errors!! the formula below works better: opd = QPointF(x,altitudeValue-floor(altitudeValue/altitudeScaleHeight*6)*altitudeScaleHeight/6); m_altitudescale->setTransform(QTransform::fromTranslate(opd.x(),opd.y()), false); double altitudeText = altitudeValue/altitudeScaleHeight*30; s = QString().sprintf("%.0f",altitudeText); m_altitudetext->setPlainText(s); // TODO: optimize this by skipping if not necessary... // Now update the text elements inside the scale: // (Qt documentation states that the list has the same order // as the item add order in the QGraphicsItemGroup) textList = m_altitudescale->childItems(); val = 5*floor(altitudeValue/altitudeScaleHeight*6)+20; foreach( QGraphicsItem * item, textList) { if (QGraphicsTextItem *text = qgraphicsitem_cast(item)) { QString s = (val<0) ? QString() : QString().sprintf("%.0f",val); text->setPlainText(s); val -= 5; } } //update(); if (!dialCount) dialTimer.stop(); }