qml: let ElCombobox determine implicitWidth based on the dimensions of all modelitems

electrum/gui/qml/components/controls/ElComboBox.qml

@@ -1,14 +1,42 @@
-import QtQuick.Controls 2.0
+import QtQuick 2.15
+import QtQuick.Controls 2.15
 
 ComboBox {
     id: cb
+
+    property int implicitChildrenWidth: 64
+
     // make combobox implicit width a multiple of 32, so it aligns with others
-    implicitWidth: Math.ceil(contentItem.implicitWidth/32)*32 + constants.paddingXXLarge
+    implicitWidth: Math.ceil(implicitChildrenWidth/32)*32 + 2 * constants.paddingXLarge
+
     // redefine contentItem, as the default crops the text easily
     contentItem: Label {
+        id: contentLabel
         text: cb.currentText
         padding: constants.paddingLarge
         rightPadding: constants.paddingXXLarge
         font.pixelSize: constants.fontSizeMedium
     }
+
+    // determine widest element and store in implicitChildrenWidth
+    function updateImplicitWidth() {
+        console.log('updating implicit width')
+        console.log(cb.count)
+        for (let i = 0; i < cb.count; i++) {
+            var txt = cb.textAt(i)
+            var txtwidth = fontMetrics.advanceWidth(txt)
+            console.log(txt + ' is ' + txtwidth + ' wide')
+            if (txtwidth > cb.implicitChildrenWidth) {
+                cb.implicitChildrenWidth = txtwidth
+            }
+        }
+    }
+
+    FontMetrics {
+        id: fontMetrics
+        font: contentLabel.font
+    }
+
+    Component.onCompleted: updateImplicitWidth()
+    onModelChanged: updateImplicitWidth()
 }