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-rw-r--r--examples/declarative/aspectratio/face_fit.qml26
-rw-r--r--examples/declarative/aspectratio/face_fit_animated.qml28
-rw-r--r--examples/declarative/aspectratio/pics/face.pngbin0 -> 905 bytes
-rw-r--r--examples/declarative/aspectratio/scale_and_crop.qml21
-rw-r--r--examples/declarative/aspectratio/scale_and_sidecrop.qml22
-rw-r--r--examples/declarative/aspectratio/scale_to_fit.qml21
-rw-r--r--src/declarative/util/qmlfollow.cpp29
-rw-r--r--src/declarative/util/qmlfollow.h3
8 files changed, 148 insertions, 2 deletions
diff --git a/examples/declarative/aspectratio/face_fit.qml b/examples/declarative/aspectratio/face_fit.qml
new file mode 100644
index 0000000..35c63ce
--- /dev/null
+++ b/examples/declarative/aspectratio/face_fit.qml
@@ -0,0 +1,26 @@
+// The Image primitive does not have any special handling for maintaining
+// aspect ratio. This example shows that you can provide whatever specific
+// behaviour you like.
+//
+// Here, we implement a hybrid of the "scale to fit" and "scale and crop"
+// behaviours which will crop up to 25% from *one* dimension if necessary
+// to fully scale the other. This is a realistic algorithm, for example
+// when the edges of the image contain less vital information than the
+// center - such as a face.
+//
+Rect {
+ // default size: whole image, unscaled
+ width: Image.width
+ height: Image.height
+ color: "gray"
+ clip: true
+
+ Image {
+ id: Image
+ source: "pics/face.png"
+ x: (parent.width-width*scale)/2
+ y: (parent.height-height*scale)/2
+ scale: Math.max(Math.min(parent.width/width*1.333,parent.height/height),
+ Math.min(parent.width/width,parent.height/height*1.333))
+ }
+}
diff --git a/examples/declarative/aspectratio/face_fit_animated.qml b/examples/declarative/aspectratio/face_fit_animated.qml
new file mode 100644
index 0000000..366d27b
--- /dev/null
+++ b/examples/declarative/aspectratio/face_fit_animated.qml
@@ -0,0 +1,28 @@
+// The Image primitive does not have any special handling for maintaining
+// aspect ratio. This example shows that you can provide whatever specific
+// behaviour you like.
+//
+// Here, we extend the "face_fit" example with animation to show how truly
+// diverse and usage-specific behaviours are made possible by NOT putting a
+// hard-coded aspect ratio feature into the Image primitive.
+//
+Rect {
+ // default size: whole image, unscaled
+ width: Image.width
+ height: Image.height
+ color: "gray"
+ clip: true
+
+ Image {
+ id: Image
+ source: "pics/face.png"
+ x: (parent.width-width*scale)/2
+ y: (parent.height-height*scale)/2
+ scale: Follow {
+ source: Math.max(Math.min(Image.parent.width/Image.width*1.333,Image.parent.height/Image.height),
+ Math.min(Image.parent.width/Image.width,Image.parent.height/Image.height*1.333))
+ spring: 1
+ damping: 0.05
+ }
+ }
+}
diff --git a/examples/declarative/aspectratio/pics/face.png b/examples/declarative/aspectratio/pics/face.png
new file mode 100644
index 0000000..9623b1a
--- /dev/null
+++ b/examples/declarative/aspectratio/pics/face.png
Binary files differ
diff --git a/examples/declarative/aspectratio/scale_and_crop.qml b/examples/declarative/aspectratio/scale_and_crop.qml
new file mode 100644
index 0000000..a5409f9
--- /dev/null
+++ b/examples/declarative/aspectratio/scale_and_crop.qml
@@ -0,0 +1,21 @@
+// The Image primitive does not have any special handling for maintaining
+// aspect ratio. This example shows that you can provide whatever specific
+// behaviour you like.
+//
+// Here, we implement "Scale and Crop" behaviour.
+//
+Rect {
+ // default size: whole image, unscaled
+ width: Image.width
+ height: Image.height
+ color: "gray"
+ clip: true
+
+ Image {
+ id: Image
+ source: "pics/face.png"
+ x: (parent.width-width*scale)/2
+ y: (parent.height-height*scale)/2
+ scale: Math.max(parent.width/width,parent.height/height)
+ }
+}
diff --git a/examples/declarative/aspectratio/scale_and_sidecrop.qml b/examples/declarative/aspectratio/scale_and_sidecrop.qml
new file mode 100644
index 0000000..e076735
--- /dev/null
+++ b/examples/declarative/aspectratio/scale_and_sidecrop.qml
@@ -0,0 +1,22 @@
+// The Image primitive does not have any special handling for maintaining
+// aspect ratio. This example shows that you can provide whatever specific
+// behaviour you like.
+//
+// Here, we implement a variant of "Scale and Crop" behaviour, where we
+// crop the sides if necessary to fully fit vertically, but not the reverse.
+//
+Rect {
+ // default size: whole image, unscaled
+ width: Image.width
+ height: Image.height
+ color: "gray"
+ clip: true
+
+ Image {
+ id: Image
+ source: "pics/face.png"
+ x: (parent.width-width*scale)/2
+ y: (parent.height-height*scale)/2
+ scale: parent.height/height
+ }
+}
diff --git a/examples/declarative/aspectratio/scale_to_fit.qml b/examples/declarative/aspectratio/scale_to_fit.qml
new file mode 100644
index 0000000..61a4082
--- /dev/null
+++ b/examples/declarative/aspectratio/scale_to_fit.qml
@@ -0,0 +1,21 @@
+// The Image primitive does not have any special handling for maintaining
+// aspect ratio. This example shows that you can provide whatever specific
+// behaviour you like.
+//
+// Here, we implement "Scale to Fit" behaviour.
+//
+Rect {
+ // default size: whole image, unscaled
+ width: Image.width
+ height: Image.height
+ color: "gray"
+ clip: true
+
+ Image {
+ id: Image
+ source: "pics/face.png"
+ x: (parent.width-width*scale)/2
+ y: (parent.height-height*scale)/2
+ scale: Math.min(parent.width/width,parent.height/height)
+ }
+}
diff --git a/src/declarative/util/qmlfollow.cpp b/src/declarative/util/qmlfollow.cpp
index 998166a..8e5ae69 100644
--- a/src/declarative/util/qmlfollow.cpp
+++ b/src/declarative/util/qmlfollow.cpp
@@ -55,7 +55,7 @@ class QmlFollowPrivate : public QObjectPrivate
public:
QmlFollowPrivate()
: sourceValue(0), maxVelocity(0), lastTime(0)
- , mass(1.0), spring(0.), damping(0.), velocity(0), enabled(true), mode(Track), clock(this) {}
+ , mass(1.0), spring(0.), damping(0.), velocity(0), epsilon(0.005), enabled(true), mode(Track), clock(this) {}
QmlMetaProperty property;
qreal currentValue;
@@ -67,6 +67,7 @@ public:
qreal spring;
qreal damping;
qreal velocity;
+ qreal epsilon;
bool enabled;
enum Mode {
@@ -111,7 +112,7 @@ void QmlFollowPrivate::tick(int time)
}
currentValue += velocity * 10.0 / 1000.0;
}
- if (qAbs(velocity) < 0.5 && qAbs(sourceValue - currentValue) < 0.5) {
+ if (qAbs(velocity) < epsilon && qAbs(sourceValue - currentValue) < epsilon) {
velocity = 0.0;
currentValue = sourceValue;
clock.stop();
@@ -300,6 +301,30 @@ void QmlFollow::setDamping(qreal damping)
d->damping = damping;
}
+
+/*!
+ \qmlproperty qreal Follow::epsilon
+ This property holds the spring epsilon
+
+ The epsilon is the rate and amount of change in the value which is close enough
+ to 0 to be considered equal to zero. This will depend on the usage of the value.
+ For pixel positions, 0.25 would suffice. For scale, 0.005 will suffice.
+
+ The default is 0.005. Small performance improvements can result in tuning this
+ value.
+*/
+qreal QmlFollow::epsilon() const
+{
+ Q_D(const QmlFollow);
+ return d->epsilon;
+}
+
+void QmlFollow::setEpsilon(qreal epsilon)
+{
+ Q_D(QmlFollow);
+ d->epsilon = epsilon;
+}
+
/*!
\qmlproperty qreal Follow::followValue
The current value.
diff --git a/src/declarative/util/qmlfollow.h b/src/declarative/util/qmlfollow.h
index aac4c01..bd9363a 100644
--- a/src/declarative/util/qmlfollow.h
+++ b/src/declarative/util/qmlfollow.h
@@ -63,6 +63,7 @@ class Q_DECLARATIVE_EXPORT QmlFollow : public QmlPropertyValueSource,
Q_PROPERTY(qreal velocity READ velocity WRITE setVelocity);
Q_PROPERTY(qreal spring READ spring WRITE setSpring);
Q_PROPERTY(qreal damping READ damping WRITE setDamping);
+ Q_PROPERTY(qreal epsilon READ epsilon WRITE setEpsilon);
Q_PROPERTY(bool enabled READ enabled WRITE setEnabled);
Q_PROPERTY(qreal followValue READ value NOTIFY valueChanged);
@@ -80,6 +81,8 @@ public:
void setSpring(qreal spring);
qreal damping() const;
void setDamping(qreal damping);
+ qreal epsilon() const;
+ void setEpsilon(qreal epsilon);
bool enabled() const;
void setEnabled(bool enabled);
generated by cgit v0.12 at 2024-11-26 17:36:06 (GMT)