Make a plain AbstractButton calculate suitable implicit size

Just like commit 87b21a57 made Control do it, this applies the same
logic to AbstractButton. The simple reasoning is that when customizing
both the contentItem and the background, it is much better to use the
AbstractButton type that does not have any default building blocks.
Previously you would have to supply implicit size calculation as well,
but this makes it much more convenient to use.

[ChangeLog][Controls][AbstractButton] A plain AbstractButton now
calculates its implicit size based on the implicit size of the content
item plus paddings, and the implicit size of the background item.

Change-Id: Ic380366b25940fbb9f28882c4622d58f4c042a07
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

3 files changed, 50 insertions, 2 deletions

diff --git a/src/imports/controls/AbstractButton.qml b/src/imports/controls/AbstractButton.qml
new file mode 100644
index 00000000..487b452b
--- /dev/null
+++ b/src/imports/controls/AbstractButton.qml
@@ -0,0 +1,48 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls 2 module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.6
+import QtQuick.Templates 2.0 as T
+
+T.AbstractButton {
+    id: control
+
+    implicitWidth: Math.max(background ? background.implicitWidth : 0,
+                            (contentItem ? contentItem.implicitWidth : 0) + leftPadding + rightPadding)
+    implicitHeight: Math.max(background ? background.implicitHeight : 0,
+                             (contentItem ? contentItem.implicitHeight : 0) + topPadding + bottomPadding)
+    baselineOffset: contentItem ? contentItem.y + contentItem.baselineOffset : 0
+}
diff --git a/src/imports/controls/controls.pri b/src/imports/controls/controls.pri
index 788bfe27..dcbcf8e1 100644
--- a/src/imports/controls/controls.pri
+++ b/src/imports/controls/controls.pri
@@ -9,6 +9,7 @@ SOURCES += \
     $$PWD/qquickdialring.cpp
 
 QML_CONTROLS = \
+    AbstractButton.qml \
     ApplicationWindow.qml \
     BusyIndicator.qml \
     Button.qml \
diff --git a/src/imports/controls/qtquickcontrols2plugin.cpp b/src/imports/controls/qtquickcontrols2plugin.cpp
index 541d18d6..153d61f7 100644
--- a/src/imports/controls/qtquickcontrols2plugin.cpp
+++ b/src/imports/controls/qtquickcontrols2plugin.cpp
@@ -41,7 +41,6 @@
 #include <QtCore/private/qfileselector_p.h>
 
 #include <QtQuickControls2/qquickstyle.h>
-#include <QtQuickTemplates2/private/qquickabstractbutton_p.h>
 #include <QtQuickTemplates2/private/qquickbuttongroup_p.h>
 #include <QtQuickTemplates2/private/qquickcontainer_p.h>
 #include <QtQuickTemplates2/private/qquickcontrol_p.h>
@@ -82,7 +81,6 @@ QtQuickControls2Plugin::QtQuickControls2Plugin(QObject *parent) : QQuickStylePlu
 
 void QtQuickControls2Plugin::registerTypes(const char *uri)
 {
-    qmlRegisterType<QQuickAbstractButton>(uri, 2, 0, "AbstractButton");
     qmlRegisterType<QQuickButtonGroup>(uri, 2, 0, "ButtonGroup");
     qmlRegisterType<QQuickButtonGroupAttached>();
 
@@ -93,6 +91,7 @@ void QtQuickControls2Plugin::registerTypes(const char *uri)
     if (!style.isEmpty())
         QFileSelectorPrivate::addStatics(QStringList() << style.toLower());
 
+    qmlRegisterType(selector.select(QStringLiteral("AbstractButton.qml")), uri, 2, 0, "AbstractButton");
     qmlRegisterType(selector.select(QStringLiteral("ApplicationWindow.qml")), uri, 2, 0, "ApplicationWindow");
     qmlRegisterType(selector.select(QStringLiteral("BusyIndicator.qml")), uri, 2, 0, "BusyIndicator");
     qmlRegisterType(selector.select(QStringLiteral("Button.qml")), uri, 2, 0, "Button");