Handling multi-platform sizing (fonts and pixels)

src/AutoPilotPlugins/PX4/FlightModesComponent.qml

@@ -364,7 +364,7 @@ Item {
 
                 QGCLabel {
                     text: "FLIGHT MODES CONFIG"
-                    font.pointSize: screenTools.dpiAdjustedPointSize(20);
+                    font.pointSize: screenTools.fontPointFactor * (20);
                 }
 
                 Item { height: 20; width: 10 } // spacer
@@ -894,7 +894,7 @@ Item {
 
                 QGCLabel {
                     text: "FLIGHT MODES CONFIG"
-                    font.pointSize: screenTools.dpiAdjustedPointSize(20);
+                    font.pointSize: screenTools.fontPointFactor * (20);
                 }
 
                 QGCLabel {

src/AutoPilotPlugins/PX4/PowerComponent.qml

@@ -98,13 +98,13 @@ Rectangle {
 
         QGCLabel {
             text: "POWER CONFIG"
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
         }
 
         QGCLabel {
             text: "Battery"
             color: palette.text
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
         }
 
         Rectangle {
@@ -231,7 +231,7 @@ Rectangle {
                 QGCLabel {
                     text: "Propeller Function"
                     color: palette.text
-                    font.pointSize: screenTools.dpiAdjustedPointSize(20);
+                    font.pointSize: screenTools.fontPointFactor * (20);
                 }
                 Rectangle {
                     width: parent.width
@@ -245,7 +245,7 @@ Rectangle {
                 QGCLabel {
                     text: "Magnetometer Distortion"
                     color: palette.text
-                    font.pointSize: screenTools.dpiAdjustedPointSize(20);
+                    font.pointSize: screenTools.fontPointFactor * (20);
                 }
                 Rectangle {
                     width: parent.width
@@ -264,7 +264,7 @@ Rectangle {
         QGCLabel {
             text: "Advanced Power Settings"
             color: palette.text
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
             visible: showAdvanced.checked
         }
         Rectangle {

src/AutoPilotPlugins/PX4/SafetyComponent.qml

@@ -54,7 +54,7 @@ Rectangle {
 
         QGCLabel {
             text: "SAFETY CONFIG"
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
         }
 
         Item { height: 20; width: 10 } // spacer
@@ -62,7 +62,7 @@ Rectangle {
         //-----------------------------------------------------------------
         //-- Return Home Triggers
 
-        QGCLabel { text: "Triggers For Return Home"; color: palette.text; font.pointSize: screenTools.dpiAdjustedPointSize(20); }
+        QGCLabel { text: "Triggers For Return Home"; color: palette.text; font.pointSize: screenTools.fontPointFactor * (20); }
 
         Item { height: 10; width: 10 } // spacer
 
@@ -121,7 +121,7 @@ Rectangle {
         //-----------------------------------------------------------------
         //-- Return Home Settings
 
-        QGCLabel { text: "Return Home Settings"; font.pointSize: screenTools.dpiAdjustedPointSize(20); }
+        QGCLabel { text: "Return Home Settings"; font.pointSize: screenTools.fontPointFactor * (20); }
 
         Item { height: 10; width: 10 } // spacer
 
@@ -291,7 +291,7 @@ Rectangle {
         QGCLabel {
             property Fact fact: Fact { name: "NAV_RCL_OBC" }
             width: parent.width
-            font.pointSize: screenTools.dpiAdjustedPointSize(14);
+            font.pointSize: screenTools.fontPointFactor * (14);
             text: "Warning: You have an advanced safety configuration set using the NAV_RCL_OBC parameter. The above settings may not apply.";
             visible: fact.value !== 0
             wrapMode: Text.Wrap
@@ -299,7 +299,7 @@ Rectangle {
         QGCLabel {
             property Fact fact: Fact { name: "NAV_DLL_OBC" }
             width: parent.width
-            font.pointSize: screenTools.dpiAdjustedPointSize(14);
+            font.pointSize: screenTools.fontPointFactor * (14);
             text: "Warning: You have an advanced safety configuration set using the NAV_DLL_OBC parameter. The above settings may not apply.";
             visible: fact.value !== 0
             wrapMode: Text.Wrap

src/AutoPilotPlugins/PX4/SensorsComponent.qml

@@ -91,7 +91,7 @@ Rectangle {
 
         QGCLabel {
             text: "SENSORS CONFIG"
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
         }
 
         Item { height: 20; width: 10 } // spacer

src/QGCApplication.cc

@@ -585,7 +585,7 @@ void QGCApplication::_loadCurrentStyle(void)
             QRegularExpressionMatch match = regex.match(line);
             if (match.hasMatch()) {
                 //qDebug() << "found:" << line << match.captured(1);
-                adjustedLine = QString("font-size: %1pt;").arg(ScreenTools::dpiAdjustedPointSize_s(match.captured(1).toDouble()));
+                adjustedLine = QString("font-size: %1pt;").arg(ScreenTools::adjustFontPointSize_s(match.captured(1).toDouble()));
                 //qDebug() << "adjusted:" << adjustedLine;
             } else {
                 adjustedLine = line;

src/QGCPalette.cc

@@ -30,8 +30,6 @@
 #include <QApplication>
 #include <QPalette>
 
-const qreal QGCPalette::_defaultFontPointSize = 12;
-
 QList<QGCPalette*>   QGCPalette::_paletteObjects;
 
 QGCPalette::Theme QGCPalette::_theme = QGCPalette::Dark;
@@ -134,7 +132,3 @@ void QGCPalette::_themeChanged(void)
     emit paletteChanged();
 }
 
-qreal QGCPalette::dpiAdjustedDefaultFontPointSize(void)
-{
-    return ScreenTools::dpiAdjustedPointSize_s(_defaultFontPointSize);
-}

src/QGCPalette.h

@@ -83,10 +83,6 @@ class QGCPalette : public QObject
     // Text color for TextFields
     Q_PROPERTY(QColor textFieldText READ textFieldText NOTIFY paletteChanged)
     
-    Q_PROPERTY(qreal defaultFontPointSize MEMBER _defaultFontPointSize CONSTANT)
-    
-    Q_PROPERTY(qreal dpiAdjustedDefaultFontPointSize READ dpiAdjustedDefaultFontPointSize CONSTANT)
-    
 public:
     enum ColorGroup {
         Disabled = 0,
@@ -123,9 +119,7 @@ public:
     
     static Theme globalTheme(void) { return _theme; }
     static void setGlobalTheme(Theme newTheme);
-    
-    qreal dpiAdjustedDefaultFontPointSize(void);
-    
+
 signals:
     void paletteChanged(void);
     
@@ -155,8 +149,6 @@ private:
     static QColor _textField[_cThemes][_cColorGroups];
     static QColor _textFieldText[_cThemes][_cColorGroups];
     
-    static const qreal _defaultFontPointSize;
-    
     void _themeChanged(void);
     
     static QList<QGCPalette*>   _paletteObjects;    ///< List of all active QGCPalette objects

src/QmlControls/ParameterEditor.qml

@@ -182,7 +182,7 @@ property Fact __propertiesDialogFact: Fact { }
 
 						QGCLabel {
 							text: "Component #: " + componentId.toString()
-							font.pointSize: __screenTools.dpiAdjustedPointSize(__qgcPal.defaultFontPointSize + 4);
+                            font.pointSize: __screenTools.fontPointFactor * (16);
 						}
 
                         Item {
@@ -214,7 +214,7 @@ property Fact __propertiesDialogFact: Fact { }
                                                 x:					__leftMargin
                                                 text:				modelData
                                                 verticalAlignment:	Text.AlignVCenter
-                                                font.pointSize:		__screenTools.dpiAdjustedPointSize(__qgcPal.defaultFontPointSize + 2);
+                                                font.pointSize:		__screenTools.fontPointFactor * (__qgcPal.defaultFontPointSize + 2);
                                             }
                                         }
 

src/QmlControls/QGCButton.qml

@@ -104,9 +104,9 @@ Button {
 
                     Text {
                         id:             text
-                        renderType:     Text.NativeRendering
+                        antialiasing:   true
                         text:           control.text
-                        font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+                        font.pointSize: __screenTools.defaultFontPointSize
 
                         anchors.verticalCenter: parent.verticalCenter
 

src/QmlControls/QGCCheckBox.qml

@@ -3,9 +3,11 @@ import QtQuick.Controls 1.2
 import QtQuick.Controls.Styles 1.2
 
 import QGroundControl.Palette 1.0
+import QGroundControl.ScreenTools 1.0
 
 CheckBox {
     property var __qgcPal: QGCPalette { colorGroupEnabled: enabled }
+    property ScreenTools __screenTools: ScreenTools { }
 
     style: CheckBoxStyle {
         label: Item {
@@ -27,7 +29,8 @@ CheckBox {
             Text {
                 id:             text
                 text:           control.text
-                font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+                antialiasing:   true
+                font.pointSize: __screenTools.defaultFontPointSize
 
                 anchors.centerIn: parent
 

src/QmlControls/QGCComboBox.qml

@@ -4,14 +4,15 @@ import QtQuick.Controls.Styles 1.2
 import QtQuick.Controls.Private 1.0
 
 import QGroundControl.Palette 1.0
+import QGroundControl.ScreenTools 1.0
 
 ComboBox {
     property var __qgcPal: QGCPalette { colorGroupEnabled: enabled }
-
+    property ScreenTools __screenTools: ScreenTools { }
     property bool __showHighlight: pressed | hovered
 
     style: ComboBoxStyle {
-		font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+        font.pointSize: __screenTools.defaultFontPointSize
         textColor: __showHighlight ?
                     control.__qgcPal.buttonHighlightText :
                     control.__qgcPal.buttonText

src/QmlControls/QGCLabel.qml

@@ -3,12 +3,15 @@ import QtQuick.Controls 1.2
 import QtQuick.Controls.Styles 1.2
 
 import QGroundControl.Palette 1.0
+import QGroundControl.ScreenTools 1.0
 
 Text {
     QGCPalette { id: __qgcPal; colorGroupEnabled: enabled }
+    property ScreenTools __screenTools: ScreenTools { }
 
     property bool enabled: true
 
-    font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+    font.pointSize: __screenTools.defaultFontPointSize
     color:          __qgcPal.text
+    antialiasing:   true
 }

src/QmlControls/QGCMovableItem.qml

 import QtQuick 2.2
 import QtQuick.Controls 1.2
+import QGroundControl.ScreenTools 1.0
 
 // This item can be dragged around within its parent.
 // Double click issues a signal the parent can use to
@@ -7,9 +8,10 @@ import QtQuick.Controls 1.2
 
 Item {
     id: root
+    property ScreenTools __screenTools: ScreenTools { }
     property bool   allowDragging:  true
-    property real   minimumWidth:   60
-    property real   minimumHeight:  60
+    property real   minimumWidth:   __screenTools.pixelSizeFactor * (60)
+    property real   minimumHeight:  __screenTools.pixelSizeFactor * (60)
     property alias  tForm:          tform
     signal          resetRequested()
     transform: Scale {

src/QmlControls/QGCRadioButton.qml

@@ -3,9 +3,11 @@ import QtQuick.Controls 1.2
 import QtQuick.Controls.Styles 1.2
 
 import QGroundControl.Palette 1.0
+import QGroundControl.ScreenTools 1.0
 
 RadioButton {
     property var __qgcPal: QGCPalette { colorGroupEnabled: enabled }
+    property ScreenTools __screenTools: ScreenTools { }
 
     style: RadioButtonStyle {
         label: Item {
@@ -27,7 +29,8 @@ RadioButton {
             Text {
                 id:             text
                 text:           control.text
-                font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+                font.pointSize: __screenTools.defaultFontPointSize
+                antialiasing:   true
 
                 anchors.centerIn: parent
 

src/QmlControls/QGCTextField.qml

@@ -3,12 +3,14 @@ import QtQuick.Controls 1.2
 import QtQuick.Controls.Styles 1.2
 
 import QGroundControl.Palette 1.0
+import QGroundControl.ScreenTools 1.0
 
 TextField {
     property bool showUnits: false
     property string unitsLabel: ""
 
     property var __qgcPal: QGCPalette { colorGroupEnabled: enabled }
+    property ScreenTools __screenTools: ScreenTools { }
 
     textColor: __qgcPal.textFieldText
 
@@ -17,6 +19,7 @@ TextField {
         text: unitsLabel
         width: contentWidth + ((parent.__contentHeight/3)*2)
         visible: false
+        antialiasing: true
     }
 
     style: TextFieldStyle {
@@ -31,7 +34,6 @@ TextField {
 
             Rectangle {
                 anchors.fill: parent
-
                 border.color: control.activeFocus ? "#47b" : "#999"
                 color: __qgcPal.textField
             }
@@ -49,7 +51,8 @@ TextField {
                 width: unitsLabelWidthGenerator.width
 
                 text: control.unitsLabel
-                font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+                font.pointSize: __screenTools.defaultFontPointSize
+                antialiasing:   true
 
                 color: control.textColor
                 visible: control.showUnits

src/QmlControls/QGCToolBarButton.qml

@@ -54,11 +54,10 @@ QGCButton {
                 }
             }
         }
-        label: Label {
+        label: QGCLabel {
             text: button.text
-            font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
             horizontalAlignment: Text.AlignHCenter
-            verticalAlignment: Text.AlignVCenter
+            verticalAlignment:   Text.AlignVCenter
             color: showHighlight ? __qgcPal.buttonHighlightText : (button.checked ? __qgcPal.primaryButtonText : __qgcPal.buttonText)
         }
     }

src/QmlControls/ScreenTools.cc

@@ -30,43 +30,82 @@
 #include <QFont>
 #include <QFontMetrics>
 
-bool ScreenTools::_dpiFactorSet = false;
-double ScreenTools::_dotsPerInch = 96.0;
-double ScreenTools::_dpiFactor = 72.0 / 96.0;
+const double ScreenTools::_defaultFontPointSize = 12;
 
 ScreenTools::ScreenTools()
 {
-    connect(MainWindow::instance(), &MainWindow::repaintCanvas, this, &ScreenTools::_updateCanvas);
+    connect(MainWindow::instance(), &MainWindow::repaintCanvas,     this, &ScreenTools::_updateCanvas);
+    connect(MainWindow::instance(), &MainWindow::pixelSizeChanged,  this, &ScreenTools::_updatePixelSize);
+    connect(MainWindow::instance(), &MainWindow::fontSizeChanged,   this, &ScreenTools::_updateFontSize);
 }
 
-qreal ScreenTools::dpiAdjustedPointSize(qreal pointSize)
+qreal ScreenTools::adjustFontPointSize(qreal pointSize)
 {
-    return dpiAdjustedPointSize_s(pointSize);
+    return adjustFontPointSize_s(pointSize);
 }
 
-qreal ScreenTools::dpiAdjustedPointSize_s(qreal pointSize)
+qreal ScreenTools::adjustFontPointSize_s(qreal pointSize)
 {
-    _setDpiFactor();
-    return pointSize * _dpiFactor;
+    return pointSize * MainWindow::fontPointFactor();
 }
 
-void ScreenTools::_setDpiFactor(void)
+qreal ScreenTools::adjustPixelSize(qreal pixelSize)
 {
-    if (!_dpiFactorSet) {
-        _dpiFactorSet = true;
-        
-        // Get screen DPI to manage font sizes on different platforms
-        QScreen *srn = QGuiApplication::primaryScreen();
-        if(srn && srn->logicalDotsPerInch() > 50.0) {
-            _dotsPerInch = (double)srn->logicalDotsPerInch(); // Font point sizes are based on Mac 72dpi
-            _dpiFactor = 72.0 / _dotsPerInch;
-        } else {
-            qWarning() << "System not reporting logical DPI, which is used to compute the appropriate font size. The default being used is 96dpi. If the text within buttons and UI elements are too big or too small, that's the reason.";
-        }
-    }
+    return adjustPixelSize_s(pixelSize);
+}
+
+qreal ScreenTools::adjustPixelSize_s(qreal pixelSize)
+{
+    return pixelSize * MainWindow::pixelSizeFactor();
+}
+
+void ScreenTools::increasePixelSize()
+{
+    MainWindow::instance()->setPixelSizeFactor(MainWindow::pixelSizeFactor() + 0.025);
+}
+
+void ScreenTools::decreasePixelSize()
+{
+    MainWindow::instance()->setPixelSizeFactor(MainWindow::pixelSizeFactor() - 0.025);
+}
+
+void ScreenTools::increaseFontSize()
+{
+    MainWindow::instance()->setFontSizeFactor(MainWindow::fontPointFactor() + 0.025);
+}
+
+void ScreenTools::decreaseFontSize()
+{
+    MainWindow::instance()->setFontSizeFactor(MainWindow::fontPointFactor() - 0.025);
 }
 
 void ScreenTools::_updateCanvas()
 {
     emit repaintRequestedChanged();
 }
+
+void ScreenTools::_updatePixelSize()
+{
+    emit pixelSizeFactorChanged();
+}
+
+void ScreenTools::_updateFontSize()
+{
+    emit fontPointFactorChanged();
+    emit defaultFontPointSizeChanged();
+}
+
+double ScreenTools::fontPointFactor()
+{
+    return MainWindow::fontPointFactor();
+}
+
+double ScreenTools::pixelSizeFactor()
+{
+    return MainWindow::pixelSizeFactor();
+}
+
+double ScreenTools::defaultFontPointSize(void)
+{
+    return _defaultFontPointSize * MainWindow::fontPointFactor();
+}

src/QmlControls/ScreenTools.h

@@ -36,11 +36,6 @@
     @code
     import QGroundControl.ScreenTools 1.0
     @endcode
-    @remark As for the screen density functions, QtQuick provides the \c Screen type (defined in QtQuick.Window)
-    but as of Qt 5.4 (QtQuick.Window 2.2), this only works if the main window is QtQuick. As QGC is primarily
-    a Qt application and only some of its UI elements are QLM widgets, this does not work. Hence, these function
-    defined here.
-    @sa <a href="http://doc.qt.io/qt-5/qml-qtquick-window-screen.html">Screen QML Type</a>
 */
 
 /// This Qml control is used to return screen parameters
@@ -50,32 +45,6 @@ class ScreenTools : public QObject
 public:
     ScreenTools();
 
-    //! Returns the screen density in Dots Per Inch
-    Q_PROPERTY(double   screenDPI           READ screenDPI CONSTANT)
-    //! Returns a factor used to calculate the font point size to use
-    /*!
-      When defining fonts in point size, as in:
-      @code
-      Text {
-        text: "Foo Bar"
-        font.pointSize: 14
-      }
-      @endcode
-      The size is device dependent. If you define this based on a screen set to 72dpi (Mac OS), once
-      this is displayed on a different screen with a different pixel density, such as 96dpi (Windows),
-      the text will be displayed in the wrong size.
-      Use \c dpiFactor to accomodate for these differences. All font point sizes are given in 72dpi
-      and \c dpiFactor returns a factor to use for adjusting it to the current target screen.
-      @code
-      import QGroundControl.ScreenTools 1.0
-      property ScreenTools screenTools: ScreenTools { }
-      Text {
-        text: "Foo Bar"
-        font.pointSize: 14 * screenTools.dpiFactor
-      }
-      @endcode
-     */
-    Q_PROPERTY(double   dpiFactor           READ dpiFactor CONSTANT)
     //! Returns the global mouse X position
     Q_PROPERTY(int      mouseX              READ mouseX)
     //! Returns the global mouse Y position
@@ -108,35 +77,55 @@ public:
         }
       @endcode
      */
-    Q_PROPERTY(bool     repaintRequested    READ repaintRequested   NOTIFY repaintRequestedChanged)
 
-    //! Utility for adjusting font point size.
-    /*!
-      @sa dpiFactor
-     */
-    Q_INVOKABLE qreal   dpiAdjustedPointSize(qreal pointSize);
+    Q_PROPERTY(bool     repaintRequested     READ repaintRequested     NOTIFY repaintRequestedChanged)
+    //! Returns the font point size factor
+    Q_PROPERTY(double   fontPointFactor      READ fontPointFactor      NOTIFY fontPointFactorChanged)
+    //! Returns the pixel size factor
+    Q_PROPERTY(double   pixelSizeFactor      READ pixelSizeFactor      NOTIFY pixelSizeFactorChanged)
+    //! Returns the system wide default font point size (properly scaled)
+    Q_PROPERTY(double   defaultFontPointSize READ defaultFontPointSize NOTIFY defaultFontPointSizeChanged)
+
+    //! Utility for adjusting font point size. Not dynamic (no signals)
+    Q_INVOKABLE qreal   adjustFontPointSize(qreal pointSize);
+    //! Utility for adjusting pixel size. Not dynamic (no signals)
+    Q_INVOKABLE qreal   adjustPixelSize(qreal pixelSize);
+
+    //! Utility for increasing pixel size.
+    Q_INVOKABLE void    increasePixelSize();
+    //! Utility for decreasing pixel size.
+    Q_INVOKABLE void    decreasePixelSize();
+    //! Utility for increasing font size.
+    Q_INVOKABLE void    increaseFontSize();
+    //! Utility for decreasing font size.
+    Q_INVOKABLE void    decreaseFontSize();
+
+    /// Static version of adjustFontPointSize of use in C++ code
+    static qreal adjustFontPointSize_s(qreal pointSize);
+    /// Static version of adjustPixelSize of use in C++ code
+    static qreal adjustPixelSize_s(qreal pixelSize);
 
-    /// Static version of dpiAdjustedPointSize of use in C++ code
-    static qreal dpiAdjustedPointSize_s(qreal pointSize);
-    
-    double  screenDPI           () { return _dotsPerInch; }
-    double  dpiFactor           () { return _dpiFactor; }
     int     mouseX              () { return QCursor::pos().x(); }
     int     mouseY              () { return QCursor::pos().y(); }
     bool    repaintRequested    () { return true; }
+    double  fontPointFactor     ();
+    double  pixelSizeFactor     ();
+    double  defaultFontPointSize(void);
 
 signals:
     void repaintRequestedChanged();
+    void pixelSizeFactorChanged();
+    void fontPointFactorChanged();
+    void defaultFontPointSizeChanged();
 
 private slots:
     void _updateCanvas();
+    void _updatePixelSize();
+    void _updateFontSize();
 
 private:
-    static void _setDpiFactor(void);
-    
-    static bool _dpiFactorSet;
-    static double _dotsPerInch;
-    static double _dpiFactor;
+    static const double _defaultFontPointSize;
+
 };
 
 #endif

src/QmlControls/SubMenuButton.qml

@@ -4,6 +4,7 @@ import QtQuick.Controls.Styles 1.2
 import QtGraphicalEffects 1.0
 
 import QGroundControl.Palette 1.0
+import QGroundControl.ScreenTools 1.0
 
 Button {
     checkable: true
@@ -13,6 +14,7 @@ Button {
     property bool setupComplete: true
     property bool setupIndicator: true
     property string imageResource: "subMenuButtonImage.png"
+    property ScreenTools __screenTools: ScreenTools { }
 
     style: ButtonStyle {
         id: buttonStyle
@@ -39,7 +41,8 @@ Button {
                 horizontalAlignment: TextEdit.AlignHCenter
 
                 text: control.text
-                font.pointSize: __qgcPal.dpiAdjustedDefaultFontPointSize
+                font.pointSize: __screenTools.defaultFontPointSize
+                antialiasing: true
                 color: __showHighlight ? __qgcPal.buttonHighlightText : __qgcPal.buttonText
 
                 Rectangle {

src/QmlControls/VehicleRotationCal.qml

@@ -71,7 +71,7 @@ Rectangle {
             height:                 parent.height
             horizontalAlignment:    Text.AlignHCenter
             verticalAlignment:      Text.AlignBottom
-            font.pointSize:         __screenTools.dpiAdjustedPointSize(25);
+            font.pointSize:         __screenTools.fontPointFactor * (25);
             font.bold:              true
             color:                  "black"
 
@@ -82,7 +82,7 @@ Rectangle {
             height:                 parent.height
             horizontalAlignment:    Text.AlignHCenter
             verticalAlignment:      Text.AlignBottom
-            font.pointSize:         __screenTools.dpiAdjustedPointSize(25);
+            font.pointSize:         __screenTools.fontPointFactor * (25);
             color:                  calInProgress ? "yellow" : "white"
 
             text: parent.calText

src/VehicleSetup/FirmwareUpgrade.qml

@@ -51,7 +51,7 @@ Rectangle {
 
         QGCLabel {
             text: "FIRMWARE UPDATE"
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
         }
 
         Item {
@@ -119,7 +119,7 @@ Rectangle {
             height:			300
             readOnly:		true
             frameVisible:	false
-			font.pointSize: qgcPal.dpiAdjustedDefaultFontPointSize
+            font.pointSize: screenTools.defaultFontPointSize
             
 			text: qsTr("Please disconnect all vehicles from QGroundControl before selecting Upgrade.")
 

src/VehicleSetup/SetupParameterEditor.qml

@@ -44,7 +44,7 @@ Rectangle {
 
         QGCLabel {
             text: "PARAMETER EDITOR"
-            font.pointSize: screenTools.dpiAdjustedPointSize(20)
+            font.pointSize: screenTools.fontPointFactor * (20)
         }
 
         Item {

src/VehicleSetup/VehicleSummary.qml

@@ -47,7 +47,7 @@ Rectangle {
 
         QGCLabel {
             text: "VEHICLE SUMMARY"
-            font.pointSize: screenTools.dpiAdjustedPointSize(20);
+            font.pointSize: screenTools.fontPointFactor * (20);
         }
 
         Item {
@@ -60,7 +60,7 @@ Rectangle {
             width:			parent.width
 			wrapMode:		Text.WordWrap
 			color:			autopilot.setupComplete ? qgcPal.text : "red"
-			font.pointSize: autopilot.setupComplete ? qgcPal.dpiAdjustedDefaultFontPointSize : screenTools.dpiAdjustedPointSize(20)
+            font.pointSize: autopilot.setupComplete ? screenTools.defaultFontPointSize : screenTools.fontPointFactor * (20)
 			text: autopilot.setupComplete ?
 						"Below you will find a summary of the settings for your vehicle. To the left are the setup buttons for deatiled settings for each component." :
 						"WARNING: One or more of your vehicle's components require setup prior to flight. It will be shown with a red circular indicator below. " +

src/ui/MainWindow.cc

@@ -82,6 +82,26 @@ This file is part of the QGROUNDCONTROL project
 
 #include "LogCompressor.h"
 
+// Pixel size, instead of a physical thing is actually a philosophical question when
+// it comes to Qt. Fonts are that and some heavy Kabalistic Voodoo added to the mix.
+// The values below came from actually measuring the elements on the screen on these
+// devices. I have yet to find a constant from Qt so these things can be properly
+// computed at runtime.
+
+#if defined(Q_OS_OSX)
+double MainWindow::_pixelFactor    = 1.0;
+double MainWindow::_fontFactor     = 1.0;
+#elif defined(Q_OS_WIN)
+double MainWindow::_pixelFactor    = 0.86;
+double MainWindow::_fontFactor     = 0.63;
+#elif defined(__android__)
+double MainWindow::_pixelFactor    = 2.0;
+double MainWindow::_fontFactor     = 1.23;
+#elif defined(Q_OS_LINUX)
+double MainWindow::_pixelFactor    = 1.0;
+double MainWindow::_fontFactor     = 0.85;
+#endif
+
 /// The key under which the Main Window settings are saved
 const char* MAIN_SETTINGS_GROUP = "QGC_MAINWINDOW";
 
@@ -226,6 +246,8 @@ MainWindow::MainWindow(QSplashScreen* splashScreen)
     emit initStatusChanged(tr("Restoring last view state"), Qt::AlignLeft | Qt::AlignBottom, QColor(62, 93, 141));
     // Restore the window setup
     _loadCurrentViewState();
+#ifndef __android__
+
     // Restore the window position and size
     emit initStatusChanged(tr("Restoring last window size"), Qt::AlignLeft | Qt::AlignBottom, QColor(62, 93, 141));
     if (settings.contains(_getWindowGeometryKey()))
@@ -265,6 +287,8 @@ MainWindow::MainWindow(QSplashScreen* splashScreen)
     // And that they will stay checked properly after user input
     connect(_ui.actionFullscreen, &QAction::triggered, this, &MainWindow::fullScreenActionItemCallback);
     connect(_ui.actionNormal,     &QAction::triggered, this, &MainWindow::normalActionItemCallback);
+#endif
+
     connect(_ui.actionStatusBar,  &QAction::triggered, this, &MainWindow::showStatusBarCallback);
 
     // Set OS dependent keyboard shortcuts for the main window, non OS dependent shortcuts are set in MainWindow.ui
@@ -295,6 +319,9 @@ MainWindow::MainWindow(QSplashScreen* splashScreen)
     if (!qgcApp()->runningUnitTests()) {
         _ui.actionStatusBar->setChecked(_showStatusBar);
         showStatusBarCallback(_showStatusBar);