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>

2 files changed, 108 insertions, 10 deletions

diff --git a/tests/auto/controls/data/tst_textarea.qml b/tests/auto/controls/data/tst_textarea.qml
index 0b0bcd20..5acd249d 100644
--- a/tests/auto/controls/data/tst_textarea.qml
+++ b/tests/auto/controls/data/tst_textarea.qml
@@ -87,14 +87,63 @@ TestCase {
         compare(implicitHeightSpy.count, 1)
     }
 
-    function test_alignment() {
-        var control = createTemporaryObject(textArea, testCase)
+    function test_alignment_data() {
+        return [
+            { tag: "empty", text: "", placeholderText: "", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,left", text: "", placeholderText: "", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,center", text: "", placeholderText: "", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "empty,right", text: "", placeholderText: "", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "empty,ltr", text: "", placeholderText: "Search", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,ltr,left", text: "", placeholderText: "Search", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,ltr,center", text: "", placeholderText: "Search", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "empty,ltr,right", text: "", placeholderText: "Search", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "empty,rtl", text: "", placeholderText: "بحث", textAlignment: undefined, placeholderAlignment: Qt.AlignRight },
+            { tag: "empty,rtl,left", text: "", placeholderText: "بحث", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,rtl,center", text: "", placeholderText: "بحث", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "empty,rtl,right", text: "", placeholderText: "بحث", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "ltr,empty", text: "Text", placeholderText: "", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,empty,left", text: "Text", placeholderText: "", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,empty,center", text: "Text", placeholderText: "", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "ltr,empty,right", text: "Text", placeholderText: "", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "ltr,ltr", text: "Text", placeholderText: "Search", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,ltr,left", text: "Text", placeholderText: "Search", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,ltr,center", text: "Text", placeholderText: "Search", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "ltr,ltr,right", text: "Text", placeholderText: "Search", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "ltr,rtl", text: "Text", placeholderText: "بحث", textAlignment: undefined, placeholderAlignment: Qt.AlignRight },
+            { tag: "ltr,rtl,left", text: "Text", placeholderText: "بحث", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,rtl,center", text: "Text", placeholderText: "بحث", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "ltr,rtl,right", text: "Text", placeholderText: "بحث", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "rtl,empty", text: "نص", placeholderText: "", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,empty,left", text: "نص", placeholderText: "", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,empty,center", text: "نص", placeholderText: "", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "rtl,empty,right", text: "نص", placeholderText: "", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "rtl,ltr", text: "نص", placeholderText: "Search", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,ltr,left", text: "نص", placeholderText: "Search", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,ltr,center", text: "نص", placeholderText: "Search", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "rtl,ltr,right", text: "نص", placeholderText: "Search", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "rtl,rtl", text: "نص", placeholderText: "بحث", textAlignment: undefined, placeholderAlignment: Qt.AlignRight },
+            { tag: "rtl,rtl,left", text: "نص", placeholderText: "بحث", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,rtl,center", text: "نص", placeholderText: "بحث", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "rtl,rtl,right", text: "نص", placeholderText: "بحث", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+        ]
+    }
+
+    function test_alignment(data) {
+        var control = createTemporaryObject(textArea, testCase, {text: data.text, placeholderText: data.placeholderText, horizontalAlignment: data.textAlignment})
 
-        control.horizontalAlignment = TextArea.AlignRight
-        compare(control.horizontalAlignment, TextArea.AlignRight)
+        if (data.textAlignment !== undefined)
+            compare(control.horizontalAlignment, data.textAlignment)
         for (var i = 0; i < control.children.length; ++i) {
             if (control.children[i].hasOwnProperty("horizontalAlignment"))
-                compare(control.children[i].horizontalAlignment, Text.AlignRight) // placeholder
+                compare(control.children[i].effectiveHorizontalAlignment, data.placeholderAlignment) // placeholder
         }
 
         control.verticalAlignment = TextArea.AlignBottom
diff --git a/tests/auto/controls/data/tst_textfield.qml b/tests/auto/controls/data/tst_textfield.qml
index 32ae6e80..bc988546 100644
--- a/tests/auto/controls/data/tst_textfield.qml
+++ b/tests/auto/controls/data/tst_textfield.qml
@@ -98,14 +98,63 @@ TestCase {
         compare(implicitHeightSpy.count, 2)
     }
 
-    function test_alignment() {
-        var control = createTemporaryObject(textField, testCase)
+    function test_alignment_data() {
+        return [
+            { tag: "empty", text: "", placeholderText: "", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,left", text: "", placeholderText: "", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,center", text: "", placeholderText: "", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "empty,right", text: "", placeholderText: "", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "empty,ltr", text: "", placeholderText: "Search", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,ltr,left", text: "", placeholderText: "Search", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,ltr,center", text: "", placeholderText: "Search", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "empty,ltr,right", text: "", placeholderText: "Search", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "empty,rtl", text: "", placeholderText: "بحث", textAlignment: undefined, placeholderAlignment: Qt.AlignRight },
+            { tag: "empty,rtl,left", text: "", placeholderText: "بحث", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "empty,rtl,center", text: "", placeholderText: "بحث", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "empty,rtl,right", text: "", placeholderText: "بحث", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "ltr,empty", text: "Text", placeholderText: "", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,empty,left", text: "Text", placeholderText: "", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,empty,center", text: "Text", placeholderText: "", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "ltr,empty,right", text: "Text", placeholderText: "", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "ltr,ltr", text: "Text", placeholderText: "Search", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,ltr,left", text: "Text", placeholderText: "Search", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,ltr,center", text: "Text", placeholderText: "Search", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "ltr,ltr,right", text: "Text", placeholderText: "Search", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "ltr,rtl", text: "Text", placeholderText: "بحث", textAlignment: undefined, placeholderAlignment: Qt.AlignRight },
+            { tag: "ltr,rtl,left", text: "Text", placeholderText: "بحث", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "ltr,rtl,center", text: "Text", placeholderText: "بحث", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "ltr,rtl,right", text: "Text", placeholderText: "بحث", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "rtl,empty", text: "نص", placeholderText: "", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,empty,left", text: "نص", placeholderText: "", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,empty,center", text: "نص", placeholderText: "", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "rtl,empty,right", text: "نص", placeholderText: "", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "rtl,ltr", text: "نص", placeholderText: "Search", textAlignment: undefined, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,ltr,left", text: "نص", placeholderText: "Search", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,ltr,center", text: "نص", placeholderText: "Search", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "rtl,ltr,right", text: "نص", placeholderText: "Search", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+
+            { tag: "rtl,rtl", text: "نص", placeholderText: "بحث", textAlignment: undefined, placeholderAlignment: Qt.AlignRight },
+            { tag: "rtl,rtl,left", text: "نص", placeholderText: "بحث", textAlignment: Qt.AlignLeft, placeholderAlignment: Qt.AlignLeft },
+            { tag: "rtl,rtl,center", text: "نص", placeholderText: "بحث", textAlignment: Qt.AlignHCenter, placeholderAlignment: Qt.AlignHCenter },
+            { tag: "rtl,rtl,right", text: "نص", placeholderText: "بحث", textAlignment: Qt.AlignRight, placeholderAlignment: Qt.AlignRight },
+        ]
+    }
+
+    function test_alignment(data) {
+        var control = createTemporaryObject(textField, testCase, {text: data.text, placeholderText: data.placeholderText, horizontalAlignment: data.textAlignment})
 
-        control.horizontalAlignment = TextField.AlignRight
-        compare(control.horizontalAlignment, TextField.AlignRight)
+        if (data.textAlignment !== undefined)
+            compare(control.horizontalAlignment, data.textAlignment)
         for (var i = 0; i < control.children.length; ++i) {
             if (control.children[i].hasOwnProperty("horizontalAlignment"))
-                compare(control.children[i].horizontalAlignment, Text.AlignRight) // placeholder
+                compare(control.children[i].effectiveHorizontalAlignment, data.placeholderAlignment) // placeholder
         }
 
         control.verticalAlignment = TextField.AlignBottom