Button: provide a default size for the label delegate

If the label delegate has no explicit size defined, make it follow the
size of the button minus padding. This should be a convenient default
behavior that satisfies the most users, and saves a few of QML bindings.
Makes also the upcoming "the default delegate implementation looks like
this" -snippet nice and short. ;)

Change-Id: I574439c1e52c2904746be7d830f9536d4cfd9083
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@theqtcompany.com>

1 files changed, 39 insertions, 1 deletions

diff --git a/src/controls/qquickbutton.cpp b/src/controls/qquickbutton.cpp
index 64d7057e..65d16494 100644
--- a/src/controls/qquickbutton.cpp
+++ b/src/controls/qquickbutton.cpp
@@ -69,10 +69,25 @@ QT_BEGIN_NAMESPACE
 */
 
 QQuickButtonPrivate::QQuickButtonPrivate() :
-    pressed(false), label(Q_NULLPTR)
+    pressed(false), label(Q_NULLPTR), labelHasWidth(true), labelHasHeight(true)
 {
 }
 
+void QQuickButtonPrivate::updateGeometry()
+{
+    Q_Q(QQuickButton);
+    if (label) {
+        if (!labelHasWidth) {
+            label->setX(q->leftPadding());
+            label->setWidth(q->width() - q->leftPadding() - q->rightPadding());
+        }
+        if (!labelHasHeight) {
+            label->setY(q->topPadding());
+            label->setHeight(q->height() - q->topPadding() - q->bottomPadding());
+        }
+    }
+}
+
 QQuickButton::QQuickButton(QQuickItem *parent) :
     QQuickControl(*(new QQuickButtonPrivate), parent)
 {
@@ -208,4 +223,27 @@ void QQuickButton::mouseUngrabEvent()
     setPressed(false);
 }
 
+void QQuickButton::componentComplete()
+{
+    Q_D(QQuickButton);
+    QQuickControl::componentComplete();
+    d->labelHasWidth = d->label && QQuickItemPrivate::get(d->label)->widthValid;
+    d->labelHasHeight = d->label && QQuickItemPrivate::get(d->label)->heightValid;
+    d->updateGeometry();
+}
+
+void QQuickButton::paddingChange()
+{
+    Q_D(QQuickButton);
+    QQuickControl::paddingChange();
+    d->updateGeometry();
+}
+
+void QQuickButton::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
+{
+    Q_D(QQuickButton);
+    QQuickControl::geometryChanged(newGeometry, oldGeometry);
+    d->updateGeometry();
+}
+
 QT_END_NAMESPACE