ComboBox: Allow setting currentIndex to -1 to clear selectionv5.2.1

Task-number: QTBUG-35794
[ChangeLog][QtQuickControls]ComboBox: Allow setting currentIndex to -1 to clear selection

Change-Id: I034b061484ab095a9ec049fb3b35614b98bfb956
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>

2 files changed, 39 insertions, 3 deletions

diff --git a/src/controls/ComboBox.qml b/src/controls/ComboBox.qml
index 974af0ae..74def897 100644
--- a/src/controls/ComboBox.qml
+++ b/src/controls/ComboBox.qml
@@ -119,6 +119,9 @@ Control {
     /*! \qmlproperty int ComboBox::currentIndex
         The index of the currently selected item in the ComboBox.
 
+        Setting currentIndex to \c -1 will reset the selection and clear the text
+        label. If \l editable is \c true, you may also need to manually clear \l editText.
+
         \sa model
     */
     property alias currentIndex: popup.__selectedIndex
@@ -342,7 +345,6 @@ Control {
         enabled: editable
         focus: true
         clip: contentWidth > width
-        text: currentText
 
         anchors.fill: parent
         anchors.leftMargin: 8
@@ -358,9 +360,11 @@ Control {
         onAccepted: {
             var idx = input.find(editText, Qt.MatchFixedString)
             if (idx > -1) {
+                editTextMatches = true;
                 currentIndex = idx;
                 editText = textAt(idx);
             } else {
+                editTextMatches = false;
                 currentIndex = -1;
                 popup.currentText = editText;
             }
@@ -369,6 +373,7 @@ Control {
 
         property bool blockUpdate: false
         property string prevText
+        property bool editTextMatches: true
 
         function find (text, searchType) {
             for (var i = 0 ; i < popupItems.count ; ++i) {
@@ -437,6 +442,13 @@ Control {
         }
     }
 
+    Binding {
+        target: input
+        property: "text"
+        value: popup.currentText
+        when: input.editTextMatches
+    }
+
     onTextRoleChanged: popup.resolveTextValue(textRole)
 
     Menu {
@@ -449,7 +461,12 @@ Control {
         onSelectedTextChanged: if (selectedText) popup.currentText = selectedText
 
         property string selectedText
-        on__SelectedIndexChanged: updateSelectedText()
+        on__SelectedIndexChanged: {
+            if (__selectedIndex === -1)
+                popup.currentText = ""
+            else
+                updateSelectedText()
+        }
         property string textRole: ""
 
         property bool ready: false
@@ -559,8 +576,10 @@ Control {
 
         function updateSelectedText() {
             var selectedItem;
-            if (__selectedIndex !== -1 && (selectedItem = items[__selectedIndex]))
+            if (__selectedIndex !== -1 && (selectedItem = items[__selectedIndex])) {
+                input.editTextMatches = true
                 selectedText = selectedItem.text
+            }
         }
     }
 
diff --git a/tests/auto/controls/data/tst_combobox.qml b/tests/auto/controls/data/tst_combobox.qml
index fde8444c..6758c982 100644
--- a/tests/auto/controls/data/tst_combobox.qml
+++ b/tests/auto/controls/data/tst_combobox.qml
@@ -680,5 +680,22 @@ TestCase {
         }
         return index
     }
+
+    function test_minusOneIndexResetsSelection_QTBUG_35794() {
+        var qmlObjects = ['import QtQuick.Controls 1.1 ; ComboBox { model: ["A", "B", "C"] }',
+                          'import QtQuick.Controls 1.1 ; ComboBox { editable: true; model: ["A", "B", "C"] }']
+        for (var i = 0; i < qmlObjects.length; i++) {
+            var comboBox = Qt.createQmlObject(qmlObjects[i], testCase, '');
+            compare(comboBox.currentIndex, 0)
+            compare(comboBox.currentText, "A")
+            comboBox.currentIndex = -1
+            compare(comboBox.currentIndex, -1)
+            compare(comboBox.currentText, "")
+            comboBox.currentIndex = 1
+            compare(comboBox.currentIndex, 1)
+            compare(comboBox.currentText, "B")
+            comboBox.destroy()
+        }
+    }
 }
 }