Add readonly visual min and max properties to QValueAxis and QDateTimeAxis

Task-number: QTBUG-142046
Change-Id: I25ab89809d28f3efa27bc83a7a455d3ab2a82a90
Reviewed-by: Sami Varanka <sami.varanka@qt.io>
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>

src/graphs2d/axis/datetimeaxis/qdatetimeaxis.cpp

@@ -332,6 +332,7 @@ void QDateTimeAxis::setZoom(qreal zoom)
     }
 
     d->m_zoom = zoom;
+    d->calculateVisualRange();
     emit zoomChanged(zoom);
     emit update();
 }
@@ -352,6 +353,7 @@ void QDateTimeAxis::setPan(qreal pan)
     }
 
     d->m_pan = pan;
+    d->calculateVisualRange();
     emit panChanged(pan);
     emit update();
 }
@@ -362,6 +364,18 @@ qreal QDateTimeAxis::pan() const
     return d->m_pan;
 }
 
+QDateTime QDateTimeAxis::visualMin() const
+{
+    Q_D(const QDateTimeAxis);
+    return QDateTime::fromMSecsSinceEpoch(d->m_visualMin, d->m_timeZone);
+}
+
+QDateTime QDateTimeAxis::visualMax() const
+{
+    Q_D(const QDateTimeAxis);
+    return QDateTime::fromMSecsSinceEpoch(d->m_visualMax, d->m_timeZone);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 QDateTimeAxisPrivate::QDateTimeAxisPrivate() {}
@@ -407,8 +421,30 @@ void QDateTimeAxisPrivate::setRange(qreal min, qreal max)
         emit q->maxChanged(QDateTime::fromMSecsSinceEpoch(max, QTimeZone::UTC));
     }
 
-    if (changed)
+    if (changed) {
+        calculateVisualRange();
         emit q->rangeChanged(min, max);
+    }
+}
+
+void QDateTimeAxisPrivate::calculateVisualRange()
+{
+    Q_Q(QDateTimeAxis);
+    qreal diff = m_max - m_min;
+    qreal center = diff / 2.0f + m_min + m_pan;
+    diff /= m_zoom;
+    qreal max = center + diff / 2.0f;
+    qreal min = center - diff / 2.0f;
+
+    if (!qFuzzyCompare(m_visualMin, min)) {
+        m_visualMin = min;
+        emit q->visualMinChanged(min);
+    }
+
+    if (!qFuzzyCompare(m_visualMax, max)) {
+        m_visualMax = max;
+        emit q->visualMaxChanged(max);
+    }
 }
 
 QT_END_NAMESPACE

src/graphs2d/axis/datetimeaxis/qdatetimeaxis.h

@@ -25,6 +25,8 @@ class Q_GRAPHS_EXPORT QDateTimeAxis : public QAbstractAxis
         QString timeZone READ timeZone WRITE setTimeZone NOTIFY timeZoneChanged REVISION(6, 11))
     Q_PROPERTY(qreal zoom READ zoom WRITE setZoom NOTIFY zoomChanged REVISION(6, 11))
     Q_PROPERTY(qreal pan READ pan WRITE setPan NOTIFY panChanged REVISION(6, 11))
+    Q_PROPERTY(QDateTime visualMin READ visualMin NOTIFY visualMinChanged REVISION(6, 11))
+    Q_PROPERTY(QDateTime visualMax READ visualMax NOTIFY visualMaxChanged REVISION(6, 11))
 
     QML_NAMED_ELEMENT(DateTimeAxis)
 
@@ -62,6 +64,9 @@ public:
     qreal pan() const;
     void setPan(qreal pan);
 
+    QDateTime visualMin() const;
+    QDateTime visualMax() const;
+
 Q_SIGNALS:
     void minChanged(const QDateTime &min);
     void maxChanged(const QDateTime &max);
@@ -71,6 +76,8 @@ Q_SIGNALS:
     Q_REVISION(6, 11) void timeZoneChanged(const QString &timeZone);
     Q_REVISION(6, 11) void zoomChanged(qreal zoom);
     Q_REVISION(6, 11) void panChanged(qreal pan);
+    Q_REVISION(6, 11) void visualMinChanged(qreal min);
+    Q_REVISION(6, 11) void visualMaxChanged(qreal max);
 
 private:
     Q_DECLARE_PRIVATE(QDateTimeAxis)

src/graphs2d/axis/datetimeaxis/qdatetimeaxis_p.h

@@ -33,6 +33,8 @@ protected:
     QString m_format = QStringLiteral("dd-MMMM-yy");
     qreal m_zoom = 1.0;
     qreal m_pan = 0.0;
+    qreal m_visualMin;
+    qreal m_visualMax;
 
 public:
     void setMin(const QVariant &min) override;
@@ -41,6 +43,7 @@ public:
     void setRange(qreal min, qreal max) override;
     qreal min() override { return m_min; }
     qreal max() override { return m_max; }
+    void calculateVisualRange();
 
 private:
     Q_DECLARE_PUBLIC(QDateTimeAxis)

src/graphs2d/axis/valueaxis/qvalueaxis.cpp

@@ -366,6 +366,7 @@ void QValueAxis::setZoom(qreal zoom)
     Q_D(QValueAxis);
     if (d->m_zoom != zoom) {
         d->m_zoom = zoom;
+        d->calculateVisualRange();
         emit update();
         emit zoomChanged(zoom);
     } else {
@@ -385,6 +386,7 @@ void QValueAxis::setPan(qreal pan)
     Q_D(QValueAxis);
     if (d->m_pan != pan) {
         d->m_pan = pan;
+        d->calculateVisualRange();
         emit update();
         emit panChanged(pan);
     } else {
@@ -399,6 +401,18 @@ qreal QValueAxis::pan() const
     return d->m_pan;
 }
 
+qreal QValueAxis::visualMin() const
+{
+    Q_D(const QValueAxis);
+    return d->m_visualMin;
+}
+
+qreal QValueAxis::visualMax() const
+{
+    Q_D(const QValueAxis);
+    return d->m_visualMax;
+}
+
 /*!
   Returns the type of the axis.
 */
@@ -477,8 +491,28 @@ void QValueAxisPrivate::setRange(qreal min, qreal max)
         emit q->maxChanged(max);
     }
 
-    if (changed)
+    if (changed) {
+        calculateVisualRange();
         emit q->rangeChanged(min, max);
+    }
+}
+
+void QValueAxisPrivate::calculateVisualRange()
+{
+    Q_Q(QValueAxis);
+    qreal diff = m_max - m_min;
+    qreal center = diff / 2.0f + m_min + m_pan;
+    diff /= m_zoom;
+    qreal min = center - diff / 2.0f;
+    qreal max = center + diff / 2.0f;
+    if (!qFuzzyCompare(m_visualMin, min)) {
+        m_visualMin = min;
+        emit q->visualMinChanged(min);
+    }
+    if (!qFuzzyCompare(m_visualMax, max)) {
+        m_visualMax = max;
+        emit q->visualMaxChanged(max);
+    }
 }
 
 QT_END_NAMESPACE

src/graphs2d/axis/valueaxis/qvalueaxis.h

@@ -28,6 +28,8 @@ class Q_GRAPHS_EXPORT QValueAxis : public QAbstractAxis
         qreal tickInterval READ tickInterval WRITE setTickInterval NOTIFY tickIntervalChanged FINAL)
     Q_PROPERTY(qreal zoom READ zoom WRITE setZoom NOTIFY zoomChanged REVISION(6, 9))
     Q_PROPERTY(qreal pan READ pan WRITE setPan NOTIFY panChanged REVISION(6, 9))
+    Q_PROPERTY(qreal visualMin READ visualMin NOTIFY visualMinChanged REVISION(6, 11))
+    Q_PROPERTY(qreal visualMax READ visualMax NOTIFY visualMaxChanged REVISION(6, 11))
     QML_NAMED_ELEMENT(ValueAxis)
 
 public:
@@ -67,6 +69,9 @@ public:
     void setPan(qreal pan);
     qreal pan() const;
 
+    qreal visualMin() const;
+    qreal visualMax() const;
+
 Q_SIGNALS:
     void minChanged(qreal min);
     void maxChanged(qreal max);
@@ -78,6 +83,8 @@ Q_SIGNALS:
     void tickIntervalChanged(qreal tickInterval);
     Q_REVISION(6, 9) void zoomChanged(qreal zoom);
     Q_REVISION(6, 9) void panChanged(qreal pan);
+    Q_REVISION(6, 11) void visualMinChanged(qreal visualMin);
+    Q_REVISION(6, 11) void visualMaxChanged(qreal visualMax);
 
 private:
     Q_DECLARE_PRIVATE(QValueAxis)

src/graphs2d/axis/valueaxis/qvalueaxis_p.h

@@ -28,6 +28,7 @@ public:
     qreal min() override { return m_min; }
     qreal max() override { return m_max; }
     void setRange(qreal min,qreal max) override;
+    void calculateVisualRange();
 
 protected:
     void setMin(const QVariant &min) override;
@@ -44,6 +45,8 @@ private:
     qreal m_tickInterval;
     qreal m_zoom = 1.0;
     qreal m_pan = 0.0;
+    qreal m_visualMin = m_min;
+    qreal m_visualMax = m_max;
     Q_DECLARE_PUBLIC(QValueAxis)
 };
 

tests/manual/qmltestbed/qml/qmltestbed/DateTimeAxis.qml

@@ -12,80 +12,109 @@ Rectangle {
     width: 800
     height: 600
     color: "#202020"
-
+    ColumnLayout {
-    RowLayout {
+        id: infoLayout
-        id:bar
+        anchors {
+            left: parent.left
+            right: parent.right
+            leftMargin: 25
+        }
         height: 100
-
+        spacing: 0
-        Text {
+        RowLayout {
-            Layout.leftMargin: 20
+            Layout.fillHeight: true
-            font.pixelSize: 24
+            Layout.fillWidth: true
-            color: "#ffffff"
+            Text {
-            text: "X:"
+                Layout.leftMargin: 20
-        }
+                font.pixelSize: 24
-
-        Slider {
-            id: sliderX
-
-            value: (new Date(1950,1,1)).getTime()
-            from: (new Date(1900,1,1)).getTime()
-            to: (new Date(2000,1,1)).getTime()
-        }
-
-        Text {
-            font.pixelSize: 24
-            color: "#ffffff"
-            text: "Y:"
-        }
-
-        Slider {
-            id: sliderY
-
-            value: (new Date(1950,1,1)).getTime()
-            from: (new Date(1900,1,1)).getTime()
-            to: (new Date(2000,1,1)).getTime()
-        }
-
-        Text {
-            Layout.leftMargin: 20
-            font.pixelSize: 24
-            color: "#ffffff"
-            text: "X Ticks:"
-        }
-
-        SpinBox {
-            onValueChanged: xAxis.tickInterval = value
-        }
-
-        Text {
-            Layout.leftMargin: 20
-            font.pixelSize: 24
-            color: "#ffffff"
-            text: "X Format:"
-        }
-        TextField {
-            placeholderText: "MMMM-yyyy"
-            onAccepted: xAxis.labelFormat = text
-        }
-
-        CheckBox {
-            id: zoomAreaEnabled
-            text: "Zoom area enabled"
-            contentItem: Text {
-                text: zoomAreaEnabled.text
-                font: zoomAreaEnabled.font
                 color: "#ffffff"
-                verticalAlignment: Text.AlignVCenter
+                text: "X:"
-                leftPadding: zoomAreaEnabled.indicator.width + zoomAreaEnabled.spacing
+            }
+            Slider {
+                id: sliderX
+                value: (new Date(1950,1,1)).getTime()
+                from: (new Date(1900,1,1)).getTime()
+                to: (new Date(2000,1,1)).getTime()
+            }
+            Text {
+                font.pixelSize: 24
+                color: "#ffffff"
+                text: "Y:"
+            }
+            Slider {
+                id: sliderY
+                value: (new Date(1950,1,1)).getTime()
+                from: (new Date(1900,1,1)).getTime()
+                to: (new Date(2000,1,1)).getTime()
+            }
+            Text {
+                Layout.leftMargin: 20
+                font.pixelSize: 24
+                color: "#ffffff"
+                text: "X Ticks:"
+            }
+            SpinBox {
+                onValueChanged: xAxis.tickInterval = value
+            }
+            Text {
+                Layout.leftMargin: 20
+                font.pixelSize: 24
+                color: "#ffffff"
+                text: "X Format:"
+            }
+            TextField {
+                placeholderText: "MMMM-yyyy"
+                onAccepted: xAxis.labelFormat = text
+            }
+            CheckBox {
+                id: zoomAreaEnabled
+                text: "Zoom area enabled"
+                contentItem: Text {
+                    text: zoomAreaEnabled.text
+                    font: zoomAreaEnabled.font
+                    color: "#ffffff"
+                    verticalAlignment: Text.AlignVCenter
+                    leftPadding: zoomAreaEnabled.indicator.width + zoomAreaEnabled.spacing
+                }
+            }
+        }
+        RowLayout {
+            Layout.fillHeight: true
+            spacing: 50
+            Column {
+                Label {
+                    id: visualXMin
+                    text: "X Axis visualMin: " + xAxis.visualMin
+                    color: "white"
+                }
+                Label {
+                    id: visualXMax
+                    text: "X Axis visualMax: " + xAxis.visualMax
+                    color: "white"
+                }
+            }
+            Column {
+                Label {
+                    id: visualYMin
+                    text: "Y Axis visualMin: " + yAxis.visualMin
+                    color: "white"
+                }
+                Label {
+                    id: visualYMax
+                    text: "Y Axis visualMax: " + yAxis.visualMax
+                    color: "white"
+                }
             }
         }
     }
 
+
+
     GraphsView {
         anchors.left: parent.left
         anchors.right: parent.right
         anchors.bottom: parent.bottom
-        anchors.top: bar.bottom
+        anchors.top: infoLayout.bottom
         anchors.margins: 10
         zoomStyle: GraphsView.ZoomStyle.Center;
         panStyle: zoomAreaEnabled.checked ? GraphsView.PanStyle.None : GraphsView.PanStyle.Drag

tests/manual/qmltestbed/qml/qmltestbed/LineProperties.qml

@@ -152,6 +152,22 @@ Rectangle {
             toValue: 40
             onSliderValueChanged: yAxis.max = sliderValue;
         }
+        CustomLabel {
+            id: visualRangeMinXLabel
+            text: qsTr("X Axis visualMin: %1").arg(Number(xAxis.visualMin).toLocaleString())
+        }
+        CustomLabel {
+            id: visualRangeMaxXLabel
+            text: qsTr("X Axis visualMax: %1").arg(Number(xAxis.visualMax).toLocaleString())
+        }
+        CustomLabel {
+            id: visualRangeMinYLabel
+            text: qsTr("Y Axis visualMin: %1").arg(Number(yAxis.visualMin).toLocaleString())
+        }
+        CustomLabel {
+            id: visualRangeMaxYLabel
+            text: qsTr("Y Axis visualMax: %1").arg(Number(yAxis.visualMax).toLocaleString())
+        }
     }
 
     GraphsView {