From 971747a31b0aba98981adc96f2ae2ae948849eff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Minisini?= <benoit.minisini@gambas-basic.org>
Date: Fri, 27 May 2022 15:48:24 +0200
Subject: [PATCH] ComboBox: The popup layout is now more clever to mimic the
 old Qt native popup behaviour.

[GB.GUI.BASE]
* NEW: ComboBox: The width of the popup now tries to fit the largest item if possible.
* NEW: ComboBox: The popup is now positioned so that it is always fully visible as much as possible. It must not work on Wayland.
---
 .../gb.gui.base/.src/ComboBox/ComboBox.class  |  2 +-
 .../.src/ComboBox/FComboBoxPopup.class        | 40 ++++++++++++++++---
 .../.src/ComboBox/FComboBoxPopup.form         |  1 -
 .../gb.gui.base/.src/Test/FTestMyCombo.form   |  6 +--
 4 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/comp/src/gb.gui.base/.src/ComboBox/ComboBox.class b/comp/src/gb.gui.base/.src/ComboBox/ComboBox.class
index 22be10730..2f2f65ec4 100644
--- a/comp/src/gb.gui.base/.src/ComboBox/ComboBox.class
+++ b/comp/src/gb.gui.base/.src/ComboBox/ComboBox.class
@@ -337,7 +337,7 @@ Public Sub ArrowBox_MouseDown()
   iIndex = Index_Read()
   
   $hPopup = New FComboBoxPopup
-  iIndex = $hPopup.Open($aList, iIndex, Me.ScreenX, Me.ScreenY + Me.H, Me.W)
+  iIndex = $hPopup.Open($aList, iIndex, Me)
   $hPopup = Null
   If iIndex >= 0 Then Index_Write(iIndex)
   Me.SetFocus
diff --git a/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.class b/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.class
index d9c03cf63..e8b6f0b6a 100644
--- a/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.class
+++ b/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.class
@@ -1,21 +1,51 @@
 ' Gambas class file
 
+Private Const MAX_ITEMS As Integer = 10
 Private $aList As String[]
 
-Public Sub Open(aList As String[], iIndex As Integer, X As Integer, Y As Integer, W As Integer) As Integer
+Public Sub Open(aList As String[], iIndex As Integer, hCtrl As Control) As Integer
   
   Dim iRow As Integer
+  Dim I As Integer
+  Dim hFont As Font
+  Dim WM As Integer
+  Dim X, Y, W, H As Integer
+  Dim hScreen As Screen
+  
+  hScreen = Screens[hCtrl.Window.Screen]
   
   $aList = aList
   
+  Me.Arrangement = Arrange.None
+  
   gvwPopup.Rows.Count = aList.Count
   gvwPopup.Columns.Count = 1
-  gvwPopup.Columns[0].Expand = True
+  'gvwPopup.Columns[0].Expand = True
+  gvwPopup.Columns[0].W = -1
   
-  W -= Style.FrameWidth * 2
-  X += Style.FrameWidth
+  W = hCtrl.W - Style.FrameWidth * 2
+  X = hCtrl.ScreenX + Style.FrameWidth
   
-  Me.Resize(W, (gvwPopup.Font.TextHeight(" ") + 6) * Min(10, $aList.Count) + 2)
+  WM = gvwPopup.Columns[0].W + 2
+  If $aList.Count > MAX_ITEMS Then WM += Style.ScrollbarSize
+  
+  W = Max(W, WM) + 2
+  H = (gvwPopup.Font.TextHeight(" ") + 6) * Min(MAX_ITEMS, $aList.Count) + 2
+  
+  Me.Arrangement = Arrange.Fill
+  
+  W = Min(W, hScreen.AvailableWidth)
+  
+  Me.Resize(W, H)
+  
+  If hCtrl.ScreenY + hCtrl.H + H > hScreen.AvailableHeight Then 
+    Y = hCtrl.ScreenY - H
+  Else 
+    Y = hCtrl.ScreenY + hCtrl.H
+  Endif
+  
+  If X + W > hScreen.AvailableWidth Then X = hScreen.AvailableWidth - W
+  If X < 0 Then X = 0
   
   Try gvwPopup.Row = iIndex
   
diff --git a/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.form b/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.form
index 5fbee1135..ded11d646 100644
--- a/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.form
+++ b/comp/src/gb.gui.base/.src/ComboBox/FComboBoxPopup.form
@@ -3,7 +3,6 @@
 { Form Form
   MoveScaled(0,0,20,25)
   Resizable = False
-  Arrangement = Arrange.Fill
   { gvwPopup GridView
     MoveScaled(2,2,16,19)
     Mode = Select.Single
diff --git a/comp/src/gb.gui.base/.src/Test/FTestMyCombo.form b/comp/src/gb.gui.base/.src/Test/FTestMyCombo.form
index b063aa78b..467aea3fc 100644
--- a/comp/src/gb.gui.base/.src/Test/FTestMyCombo.form
+++ b/comp/src/gb.gui.base/.src/Test/FTestMyCombo.form
@@ -1,18 +1,18 @@
 # Gambas Form File 3.0
 
 { Form Form
-  MoveScaled(0,0,64,64)
+  MoveScaled(0,0,30,64)
   Arrangement = Arrange.Vertical
   Spacing = True
   Margin = True
   { MyComboBox1 ComboBox
     MoveScaled(5,2,21,4)
     ReadOnly = True
-    List = [("Élément 1"), ("Élément 2"), ("Élément 3"), ("Élément 4"), ("Élément 5"), ("Élément 6"), ("Élément 7"), ("Élément 8"), ("Élément 9"), ("Élément 10"), ("Élément 11"), ("Élément 12")]
+    List = [("Élément 1"), ("Élément 2"), ("Élément 3"), ("Élément 4"), ("Élément 5"), ("Élément 6"), ("Élément 7"), ("Élément 8"), ("Élément 9"), ("Élément 10"), ("Élément 11"), ("Élément 12"), ("Élément plus long que les autres")]
   }
   { MyComboBox2 ComboBox
     MoveScaled(5,8,24,4)
-    List = [("Élément 1"), ("Élément 2"), ("Élément 3"), ("Élément 4"), ("Élément 5"), ("Élément 6"), ("Élément 7"), ("Élément 8"), ("Élément 9"), ("Élément 10"), ("Élément 11"), ("Élément 12")]
+    List = [("Élément 6"), ("Élément 7"), ("Élément 8"), ("Élément 9"), ("Élément 10"), ("Élément 11"), ("Élément 12"), ("Élément plus long que les autres")]
   }
   { MyComboBox3 ComboBox
     MoveScaled(4,13,24,4)