Android: text entry implicit size fits 20 characters

A native unlayouted EditText control fits 20 characters by default.
Let Qt Quick Controls Android Style use the same metrics instead of
adjusting to the textual contents. This gives empty TextField,
SpinBox and ComboBox sensible implicit sizes instead of shrinking
them down to something unusable.

Change-Id: I3cd3948aa3d64daada9d0b7d773cebb6627263f6
Reviewed-by: Mitch Curtis <mitch.curtis@digia.com>

src/controls/Styles/Android/ComboBoxStyle.qml

@@ -37,7 +37,7 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-import QtQuick 2.2
+import QtQuick 2.4
 import QtQuick.Window 2.2
 import QtQuick.Controls 1.2
 import QtQuick.Controls.Private 1.0
@@ -70,7 +70,7 @@ Style {
 
         readonly property real minWidth: styleDef.View_minWidth || 0
         readonly property real minHeight: styleDef.View_minHeight || 0
-        readonly property real labelWidth: label.implicitWidth + paddingStart + paddingEnd
+        readonly property real labelWidth: Math.max(label.implicitWidth, metrics.width) + paddingStart + paddingEnd
         readonly property real labelHeight: label.implicitHeight + bg.padding.top + bg.padding.bottom
 
         implicitWidth: Math.max(minWidth, Math.max(bg.implicitWidth, labelWidth))
@@ -85,6 +85,11 @@ Style {
             styleDef: panel.styleDef.View_background
         }
 
+        TextMetrics {
+            id: metrics
+            text: "12345678901234567890"
+        }
+
         LabelStyle {
             id: label
             text: control.currentText

src/controls/Styles/Android/SpinBoxStyle.qml

@@ -37,7 +37,7 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-import QtQuick 2.2
+import QtQuick 2.4
 import QtQuick.Window 2.2
 import QtQuick.Controls 1.2
 import QtQuick.Controls.Private 1.0
@@ -58,7 +58,7 @@ Style {
 
         readonly property real contentWidth: Math.max(styleDef.View_minWidth || 0, styleData.contentWidth)
         readonly property real contentHeight: Math.max(styleDef.View_minHeight || 0, styleData.contentHeight)
-        readonly property real labelWidth: label.implicitWidth + bg.padding.left + bg.padding.right
+        readonly property real labelWidth: Math.max(label.implicitWidth, metrics.width) + bg.padding.left + bg.padding.right
         readonly property real labelHeight: label.implicitHeight + bg.padding.top + bg.padding.bottom
 
         implicitWidth: Math.max(contentWidth, Math.max(bg.implicitWidth, labelWidth))
@@ -88,6 +88,11 @@ Style {
         readonly property int horizontalAlignment: Qt.AlignLeft
         readonly property int verticalAlignment: Qt.AlignVCenter
 
+        TextMetrics {
+            id: metrics
+            text: "12345678901234567890"
+        }
+
         LabelStyle {
             id: label
             visible: false

src/controls/Styles/Android/TextFieldStyle.qml

@@ -37,7 +37,7 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-import QtQuick 2.2
+import QtQuick 2.4
 import QtQuick.Window 2.2
 import QtQuick.Controls 1.2
 import QtQuick.Controls.Private 1.0
@@ -56,7 +56,7 @@ Style {
 
         readonly property real minWidth: styleDef.View_minWidth || 0
         readonly property real minHeight: styleDef.View_minHeight || 0
-        readonly property real labelWidth: label.implicitWidth + bg.padding.left + bg.padding.right
+        readonly property real labelWidth: Math.max(label.implicitWidth, metrics.width) + bg.padding.left + bg.padding.right
         readonly property real labelHeight: label.implicitHeight + bg.padding.top + bg.padding.bottom
 
         implicitWidth: Math.max(minWidth, Math.max(bg.implicitWidth, labelWidth))
@@ -81,10 +81,15 @@ Style {
         readonly property alias selectionColor: label.selectionColor
         readonly property color selectedTextColor: label.selectedTextColor
 
+        TextMetrics {
+            id: metrics
+            text: "12345678901234567890"
+        }
+
         LabelStyle {
             id: label
             visible: false
-            text: control.text
+            text: control.text || control.placeholderText
             focused: control.activeFocus
             window_focused: focused && control.Window.active
             styleDef: panel.styleDef