enhance: remember the height/width of commit list and detail panel in histories page (#472)

Author: love-linger

src/ViewModels/Histories.cs

@@ -61,6 +61,30 @@ public object DetailContext
             set => SetProperty(ref _detailContext, value);
         }
 
+        public GridLength LeftArea
+        {
+            get => _leftArea;
+            set => SetProperty(ref _leftArea, value);
+        }
+
+        public GridLength RightArea
+        {
+            get => _rightArea;
+            set => SetProperty(ref _rightArea, value);
+        }
+
+        public GridLength TopArea
+        {
+            get => _topArea;
+            set => SetProperty(ref _topArea, value);
+        }
+
+        public GridLength BottomArea
+        {
+            get => _bottomArea;
+            set => SetProperty(ref _bottomArea, value);
+        }
+
         public Histories(Repository repo)
         {
             _repo = repo;
@@ -800,5 +824,10 @@ private void FillTagMenu(ContextMenu menu, Models.Tag tag)
         private Models.Commit _autoSelectedCommit = null;
         private long _navigationId = 0;
         private object _detailContext = null;
+
+        private GridLength _leftArea = new GridLength(1, GridUnitType.Star);
+        private GridLength _rightArea = new GridLength(1, GridUnitType.Star);
+        private GridLength _topArea = new GridLength(1, GridUnitType.Star);
+        private GridLength _bottomArea = new GridLength(1, GridUnitType.Star);
     }
 }

src/Views/Histories.axaml

@@ -10,8 +10,19 @@
              x:Class="SourceGit.Views.Histories"
              x:DataType="vm:Histories"
              x:Name="ThisControl">
-  <v:LayoutableGrid RowDefinitions="*,3,*" ColumnDefinitions="*,3,*"
-                    UseHorizontal="{Binding Source={x:Static vm:Preference.Instance}, Path=UseTwoColumnsLayoutInHistories}">
+  <v:LayoutableGrid UseHorizontal="{Binding Source={x:Static vm:Preference.Instance}, Path=UseTwoColumnsLayoutInHistories}">
+    <v:LayoutableGrid.RowDefinitions>
+      <RowDefinition Height="{Binding TopArea, Mode=TwoWay}"/>
+      <RowDefinition Height="3"/>
+      <RowDefinition Height="{Binding BottomArea, Mode=TwoWay}"/>
+    </v:LayoutableGrid.RowDefinitions>
+
+    <v:LayoutableGrid.ColumnDefinitions>
+      <ColumnDefinition Width="{Binding LeftArea, Mode=TwoWay}"/>
+      <ColumnDefinition Width="3"/>
+      <ColumnDefinition Width="{Binding RightArea, Mode=TwoWay}"/>
+    </v:LayoutableGrid.ColumnDefinitions>
+    
     <Grid Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3">
       <Grid RowDefinitions="24,*">
         <!-- Headers -->