Slider: add from & to properties

Change-Id: Iee61e89d8519e7e3d27f1bf1c35af210f48bc7c9
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>

3 files changed, 191 insertions, 24 deletions

diff --git a/src/controls/qquickslider.cpp b/src/controls/qquickslider.cpp
index 5ce3cb92..889737d0 100644
--- a/src/controls/qquickslider.cpp
+++ b/src/controls/qquickslider.cpp
@@ -74,13 +74,18 @@ class QQuickSliderPrivate : public QQuickControlPrivate
     Q_DECLARE_PUBLIC(QQuickSlider)
 
 public:
-    QQuickSliderPrivate() : value(0), position(0), stepSize(0), pressed(false),
+    QQuickSliderPrivate() : from(0), to(1), value(0), position(0), stepSize(0), pressed(false),
         orientation(Qt::Horizontal), snapMode(QQuickSlider::NoSnap),
         handle(Q_NULLPTR), track(Q_NULLPTR) { }
 
+    qreal valueAt(qreal position) const;
     qreal snapPosition(qreal position) const;
     qreal positionAt(const QPoint &point) const;
+    void setPosition(qreal position);
+    void updatePosition();
 
+    qreal from;
+    qreal to;
     qreal value;
     qreal position;
     qreal stepSize;
@@ -92,6 +97,11 @@ public:
     QQuickItem *track;
 };
 
+qreal QQuickSliderPrivate::valueAt(qreal position) const
+{
+    return from + (to - from) * position;
+}
+
 qreal QQuickSliderPrivate::snapPosition(qreal position) const
 {
     if (qFuzzyIsNull(stepSize))
@@ -122,6 +132,25 @@ qreal QQuickSliderPrivate::positionAt(const QPoint &point) const
     return 0;
 }
 
+void QQuickSliderPrivate::setPosition(qreal pos)
+{
+    Q_Q(QQuickSlider);
+    pos = qBound(0.0, pos, 1.0);
+    if (!qFuzzyCompare(position, pos)) {
+        position = pos;
+        emit q->positionChanged();
+        emit q->visualPositionChanged();
+    }
+}
+
+void QQuickSliderPrivate::updatePosition()
+{
+    qreal pos = 0;
+    if (!qFuzzyCompare(from, to))
+        pos = (value - from) / (to - from);
+    setPosition(pos);
+}
+
 QQuickSlider::QQuickSlider(QQuickItem *parent) :
     QQuickControl(*(new QQuickSliderPrivate), parent)
 {
@@ -130,14 +159,65 @@ QQuickSlider::QQuickSlider(QQuickItem *parent) :
 }
 
 /*!
+    \qmlproperty real QtQuickControls2::Slider::from
+
+    This property holds the starting value for the range. The default value is \c 0.0.
+
+    \sa to, value
+*/
+qreal QQuickSlider::from() const
+{
+    Q_D(const QQuickSlider);
+    return d->from;
+}
+
+void QQuickSlider::setFrom(qreal from)
+{
+    Q_D(QQuickSlider);
+    if (!qFuzzyCompare(d->from, from)) {
+        d->from = from;
+        emit fromChanged();
+        if (isComponentComplete()) {
+            setValue(d->value);
+            d->updatePosition();
+        }
+    }
+}
+
+/*!
+    \qmlproperty real QtQuickControls2::Slider::to
+
+    This property holds the end value for the range. The default value is \c 1.0.
+
+    \sa from, value
+*/
+qreal QQuickSlider::to() const
+{
+    Q_D(const QQuickSlider);
+    return d->to;
+}
+
+void QQuickSlider::setTo(qreal to)
+{
+    Q_D(QQuickSlider);
+    if (!qFuzzyCompare(d->to, to)) {
+        d->to = to;
+        emit toChanged();
+        if (isComponentComplete()) {
+            setValue(d->value);
+            d->updatePosition();
+        }
+    }
+}
+
+/*!
     \qmlproperty real QtQuickControls2::Slider::value
 
-    This property holds the value in the range \c 0.0 - \c 1.0. The default value is \c 0.0.
+    This property holds the value in the range \c from - \c to. The default value is \c 0.0.
 
-    The value is defined as a percentage of the control's size, scaled
-    to \c 0.0 - \c 1.0. Unlike the \l position property, the \c value is
-    not updated while the handle is dragged. The value is updated after
-    the value has been chosen and the slider has been released.
+    Unlike the \l position property, the \c value is not updated while the
+    handle is dragged. The value is updated after the value has been chosen
+    and the slider has been released.
 
     \sa position
 */
@@ -150,10 +230,12 @@ qreal QQuickSlider::value() const
 void QQuickSlider::setValue(qreal value)
 {
     Q_D(QQuickSlider);
-    value = qBound(0.0, value, 1.0);
+    if (isComponentComplete())
+        value = d->from > d->to ? qBound(d->to, value, d->from) : qBound(d->from, value, d->to);
+
     if (!qFuzzyCompare(d->value, value)) {
         d->value = value;
-        setPosition(value);
+        d->updatePosition();
         emit valueChanged();
     }
 }
@@ -164,7 +246,7 @@ void QQuickSlider::setValue(qreal value)
     This property holds the logical position of the handle.
 
     The position is defined as a percentage of the control's size, scaled
-    to \c 0.0 - \c 1.0. Unlike the \l value property, the \c position is
+    to \c {0.0 - 1.0}. Unlike the \l value property, the \c position is
     continuously updated while the handle is dragged. For visualizing a
     slider, the right-to-left aware \l visualPosition should be used instead.
 
@@ -183,7 +265,7 @@ qreal QQuickSlider::position() const
     This property holds the visual position of the handle.
 
     The position is defined as a percentage of the control's size, scaled to
-    \c 0.0 - \c 1.0. When the control is \l mirrored, the value is equal to
+    \c {0.0 - 1.0}. When the control is \l mirrored, the value is equal to
     \c {1.0 - position}. This makes the value suitable for visualizing the
     slider, taking right-to-left support into account.
 
@@ -197,17 +279,6 @@ qreal QQuickSlider::visualPosition() const
     return d->position;
 }
 
-void QQuickSlider::setPosition(qreal position)
-{
-    Q_D(QQuickSlider);
-    position = qBound(0.0, position, 1.0);
-    if (!qFuzzyCompare(d->position, position)) {
-        d->position = position;
-        emit positionChanged();
-        emit visualPositionChanged();
-    }
-}
-
 /*!
     \qmlproperty real QtQuickControls2::Slider::stepSize
 
@@ -445,7 +516,7 @@ void QQuickSlider::mouseMoveEvent(QMouseEvent *event)
         qreal pos = d->positionAt(event->pos());
         if (d->snapMode == SnapAlways)
             pos = d->snapPosition(pos);
-        setPosition(pos);
+        d->setPosition(pos);
     }
     event->accept();
 }
@@ -459,7 +530,7 @@ void QQuickSlider::mouseReleaseEvent(QMouseEvent *event)
         qreal pos = d->positionAt(event->pos());
         if (d->snapMode != NoSnap)
             pos = d->snapPosition(pos);
-        setValue(pos);
+        setValue(d->valueAt(pos));
         setKeepMouseGrab(false);
     }
     setPressed(false);
@@ -480,4 +551,12 @@ void QQuickSlider::mirrorChange()
     emit visualPositionChanged();
 }
 
+void QQuickSlider::componentComplete()
+{
+    Q_D(QQuickSlider);
+    QQuickControl::componentComplete();
+    setValue(d->value);
+    d->updatePosition();
+}
+
 QT_END_NAMESPACE
diff --git a/src/controls/qquickslider_p.h b/src/controls/qquickslider_p.h
index bd5411ed..0e0f8e90 100644
--- a/src/controls/qquickslider_p.h
+++ b/src/controls/qquickslider_p.h
@@ -57,6 +57,8 @@ class QQuickSliderPrivate;
 class Q_QUICKCONTROLS_EXPORT QQuickSlider : public QQuickControl
 {
     Q_OBJECT
+    Q_PROPERTY(qreal from READ from WRITE setFrom NOTIFY fromChanged FINAL)
+    Q_PROPERTY(qreal to READ to WRITE setTo NOTIFY toChanged FINAL)
     Q_PROPERTY(qreal value READ value WRITE setValue NOTIFY valueChanged FINAL)
     Q_PROPERTY(qreal position READ position NOTIFY positionChanged FINAL)
     Q_PROPERTY(qreal visualPosition READ visualPosition NOTIFY visualPositionChanged FINAL)
@@ -70,12 +72,17 @@ class Q_QUICKCONTROLS_EXPORT QQuickSlider : public QQuickControl
 public:
     explicit QQuickSlider(QQuickItem *parent = Q_NULLPTR);
 
+    qreal from() const;
+    void setFrom(qreal from);
+
+    qreal to() const;
+    void setTo(qreal to);
+
     qreal value() const;
     void setValue(qreal value);
 
     qreal position() const;
     qreal visualPosition() const;
-    void setPosition(qreal position);
 
     qreal stepSize() const;
     void setStepSize(qreal step);
@@ -107,6 +114,8 @@ public Q_SLOTS:
     void decrease();
 
 Q_SIGNALS:
+    void fromChanged();
+    void toChanged();
     void valueChanged();
     void positionChanged();
     void visualPositionChanged();
@@ -125,6 +134,7 @@ protected:
     void mouseReleaseEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void mouseUngrabEvent() Q_DECL_OVERRIDE;
     void mirrorChange() Q_DECL_OVERRIDE;
+    void componentComplete() Q_DECL_OVERRIDE;
 
 private:
     Q_DISABLE_COPY(QQuickSlider)
diff --git a/tests/auto/controls/data/tst_slider.qml b/tests/auto/controls/data/tst_slider.qml
index 087024f6..2e9dec2b 100644
--- a/tests/auto/controls/data/tst_slider.qml
+++ b/tests/auto/controls/data/tst_slider.qml
@@ -85,6 +85,84 @@ TestCase {
         control.destroy()
     }
 
+    function test_value() {
+        var control = slider.createObject(testCase, {value: 0.5})
+        compare(control.value, 0.5)
+        control.value = 1.0
+        compare(control.value, 1.0)
+        control.value = -1.0
+        compare(control.value, 0.0)
+        control.value = 2.0
+        compare(control.value, 1.0)
+        control.destroy()
+    }
+
+    function test_range() {
+        var control = slider.createObject(testCase, {from: 0, to: 100, value: 50})
+        compare(control.from, 0)
+        compare(control.to, 100)
+        compare(control.value, 50)
+        compare(control.position, 0.5)
+
+        control.value = 1000
+        compare(control.value, 100)
+        compare(control.position, 1)
+
+        control.value = -1
+        compare(control.value, 0)
+        compare(control.position, 0)
+
+        control.from = 25
+        compare(control.from, 25)
+        compare(control.value, 25)
+        compare(control.position, 0)
+
+        control.to = 75
+        compare(control.to, 75)
+        compare(control.value, 25)
+        compare(control.position, 0)
+
+        control.value = 50
+        compare(control.value, 50)
+        compare(control.position, 0.5)
+
+        control.destroy()
+    }
+
+    function test_inverted() {
+        var control = slider.createObject(testCase, {from: 1.0, to: -1.0})
+        compare(control.from, 1.0)
+        compare(control.to, -1.0)
+        compare(control.value, 0.0)
+        compare(control.position, 0.5)
+
+        control.value = 2.0
+        compare(control.value, 1.0)
+        compare(control.position, 0.0)
+
+        control.value = -2.0
+        compare(control.value, -1.0)
+        compare(control.position, 1.0)
+
+        control.value = 0.0
+        compare(control.value, 0.0)
+        compare(control.position, 0.5)
+
+        control.destroy()
+    }
+
+    function test_position() {
+        var control = slider.createObject(testCase, {value: 0.25})
+        compare(control.value, 0.25)
+        compare(control.position, 0.25)
+
+        control.value = 0.75
+        compare(control.value, 0.75)
+        compare(control.position, 0.75)
+
+        control.destroy()
+    }
+
     function test_visualPosition() {
         var control = slider.createObject(testCase, {value: 0.25})
         compare(control.value, 0.25)