Editors: fix placeholder text alignment

The internal QQuickPlaceholderText creates an "implicit binding"
to the editor's horizontalAlignment, meaning that the placeholder
respects the editor's horizontal alignment when explicitly set,
and otherwise determines the alignment from the placeholder text's
visual direction.

[ChangeLog][Controls][TextField] Fixed the horizontal alignment
of the placeholder text in right-to-left UIs.

[ChangeLog][Controls][TextArea] Fixed the horizontal alignment
of the placeholder text in right-to-left UIs.

Task-number: QTBUG-55999
Change-Id: If1a8596c35c1920874996277520f1c54430c5f69
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

7 files changed, 16 insertions, 12 deletions

diff --git a/src/imports/controls/TextArea.qml b/src/imports/controls/TextArea.qml
index 88db299b..6a80bb69 100644
--- a/src/imports/controls/TextArea.qml
+++ b/src/imports/controls/TextArea.qml
@@ -57,7 +57,7 @@ T.TextArea {
     selectionColor: Default.textSelectionColor
     selectedTextColor: color
 
-    Text {
+    PlaceholderText {
         id: placeholder
         x: control.leftPadding
         y: control.topPadding
@@ -67,7 +67,6 @@ T.TextArea {
         text: control.placeholderText
         font: control.font
         color: Default.textDisabledLightColor
-        horizontalAlignment: control.horizontalAlignment
         verticalAlignment: control.verticalAlignment
         visible: !control.length && !control.preeditText && (!control.activeFocus || control.horizontalAlignment !== Qt.AlignHCenter)
         elide: Text.ElideRight
diff --git a/src/imports/controls/TextField.qml b/src/imports/controls/TextField.qml
index 0f665344..1e62ac55 100644
--- a/src/imports/controls/TextField.qml
+++ b/src/imports/controls/TextField.qml
@@ -58,7 +58,7 @@ T.TextField {
     selectedTextColor: color
     verticalAlignment: TextInput.AlignVCenter
 
-    Text {
+    PlaceholderText {
         id: placeholder
         x: control.leftPadding
         y: control.topPadding
@@ -68,7 +68,6 @@ T.TextField {
         text: control.placeholderText
         font: control.font
         color: Default.textDisabledColor
-        horizontalAlignment: control.horizontalAlignment
         verticalAlignment: control.verticalAlignment
         visible: !control.length && !control.preeditText && (!control.activeFocus || control.horizontalAlignment !== Qt.AlignHCenter)
         elide: Text.ElideRight
diff --git a/src/imports/controls/material/TextArea.qml b/src/imports/controls/material/TextArea.qml
index 5c4f0279..19f0cca4 100644
--- a/src/imports/controls/material/TextArea.qml
+++ b/src/imports/controls/material/TextArea.qml
@@ -36,6 +36,8 @@
 
 import QtQuick 2.9
 import QtQuick.Templates 2.2 as T
+import QtQuick.Controls 2.2
+import QtQuick.Controls.impl 2.2
 import QtQuick.Controls.Material 2.2
 import QtQuick.Controls.Material.impl 2.2
 
@@ -58,7 +60,7 @@ T.TextArea {
 
     cursorDelegate: CursorDelegate { }
 
-    Text {
+    PlaceholderText {
         id: placeholder
         x: control.leftPadding
         y: control.topPadding
@@ -67,7 +69,6 @@ T.TextArea {
         text: control.placeholderText
         font: control.font
         color: control.Material.hintTextColor
-        horizontalAlignment: control.horizontalAlignment
         verticalAlignment: control.verticalAlignment
         elide: Text.ElideRight
         visible: !control.length && !control.preeditText && (!control.activeFocus || control.horizontalAlignment !== Qt.AlignHCenter)
diff --git a/src/imports/controls/material/TextField.qml b/src/imports/controls/material/TextField.qml
index eb53992b..2d707151 100644
--- a/src/imports/controls/material/TextField.qml
+++ b/src/imports/controls/material/TextField.qml
@@ -36,6 +36,8 @@
 
 import QtQuick 2.9
 import QtQuick.Templates 2.2 as T
+import QtQuick.Controls 2.2
+import QtQuick.Controls.impl 2.2
 import QtQuick.Controls.Material 2.2
 import QtQuick.Controls.Material.impl 2.2
 
@@ -59,7 +61,7 @@ T.TextField {
 
     cursorDelegate: CursorDelegate { }
 
-    Text {
+    PlaceholderText {
         id: placeholder
         x: control.leftPadding
         y: control.topPadding
@@ -68,7 +70,6 @@ T.TextField {
         text: control.placeholderText
         font: control.font
         color: control.Material.hintTextColor
-        horizontalAlignment: control.horizontalAlignment
         verticalAlignment: control.verticalAlignment
         elide: Text.ElideRight
         visible: !control.length && !control.preeditText && (!control.activeFocus || control.horizontalAlignment !== Qt.AlignHCenter)
diff --git a/src/imports/controls/qtquickcontrols2plugin.cpp b/src/imports/controls/qtquickcontrols2plugin.cpp
index 70f6879b..95ed3776 100644
--- a/src/imports/controls/qtquickcontrols2plugin.cpp
+++ b/src/imports/controls/qtquickcontrols2plugin.cpp
@@ -36,6 +36,7 @@
 
 #include <QtCore/private/qfileselector_p.h>
 #include <QtQuickControls2/qquickstyle.h>
+#include <QtQuickControls2/private/qquickplaceholdertext_p.h>
 #include <QtQuickControls2/private/qquickstyle_p.h>
 #include <QtQuickControls2/private/qquickstyleplugin_p.h>
 #include <QtQuickControls2/private/qquickstyleselector_p.h>
@@ -163,6 +164,7 @@ void QtQuickControls2Plugin::initializeEngine(QQmlEngine *engine, const char *ur
     qmlRegisterType<QQuickDefaultBusyIndicator>(import, 2, 0, "BusyIndicatorImpl");
     qmlRegisterType<QQuickDefaultProgressBar>(import, 2, 0, "ProgressBarImpl");
     qmlRegisterType<QQuickDialRing>(import, 2, 0, "DialRing");
+    qmlRegisterType<QQuickPlaceholderText>(import, 2, 2, "PlaceholderText");
     qmlRegisterType<QQuickTumblerView>(import, 2, 1, "TumblerView");
     qmlRegisterSingletonType<QQuickDefaultStyle>(import, 2, 1, "Default", styleSingleton);
     qmlRegisterType(typeUrl(QStringLiteral("CheckIndicator.qml")), import, 2, 0, "CheckIndicator");
diff --git a/src/imports/controls/universal/TextArea.qml b/src/imports/controls/universal/TextArea.qml
index 2b38e678..8d931a96 100644
--- a/src/imports/controls/universal/TextArea.qml
+++ b/src/imports/controls/universal/TextArea.qml
@@ -36,6 +36,8 @@
 
 import QtQuick 2.9
 import QtQuick.Templates 2.2 as T
+import QtQuick.Controls 2.2
+import QtQuick.Controls.impl 2.2
 import QtQuick.Controls.Universal 2.2
 
 T.TextArea {
@@ -60,7 +62,7 @@ T.TextArea {
     selectionColor: Universal.accent
     selectedTextColor: Universal.chromeWhiteColor
 
-    Text {
+    PlaceholderText {
         id: placeholder
         x: control.leftPadding
         y: control.topPadding
@@ -72,7 +74,6 @@ T.TextArea {
         color: !control.enabled ? control.Universal.chromeDisabledLowColor :
                 control.activeFocus ? control.Universal.chromeBlackMediumLowColor : control.Universal.baseMediumColor
         visible: !control.length && !control.preeditText && (!control.activeFocus || control.horizontalAlignment !== Qt.AlignHCenter)
-        horizontalAlignment: control.horizontalAlignment
         verticalAlignment: control.verticalAlignment
         elide: Text.ElideRight
     }
diff --git a/src/imports/controls/universal/TextField.qml b/src/imports/controls/universal/TextField.qml
index 14ade06c..e28c1893 100644
--- a/src/imports/controls/universal/TextField.qml
+++ b/src/imports/controls/universal/TextField.qml
@@ -36,6 +36,8 @@
 
 import QtQuick 2.9
 import QtQuick.Templates 2.2 as T
+import QtQuick.Controls 2.2
+import QtQuick.Controls.impl 2.2
 import QtQuick.Controls.Universal 2.2
 
 T.TextField {
@@ -61,7 +63,7 @@ T.TextField {
     selectedTextColor: Universal.chromeWhiteColor
     verticalAlignment: TextInput.AlignVCenter
 
-    Text {
+    PlaceholderText {
         id: placeholder
         x: control.leftPadding
         y: control.topPadding
@@ -73,7 +75,6 @@ T.TextField {
         color: !control.enabled ? control.Universal.chromeDisabledLowColor :
                 control.activeFocus ? control.Universal.chromeBlackMediumLowColor : control.Universal.baseMediumColor
         visible: !control.length && !control.preeditText && (!control.activeFocus || control.horizontalAlignment !== Qt.AlignHCenter)
-        horizontalAlignment: control.horizontalAlignment
         verticalAlignment: control.verticalAlignment
         elide: Text.ElideRight
     }