Main form GUI tweaks (#1804)

- Added Expand All Nodes menu
- Added Collapse All Nodes menu

LibreHardwareMonitor/UI/Gadget.cs

@@ -175,4 +175,4 @@ public abstract class Gadget : IDisposable
     }
 
     protected abstract void OnPaint(PaintEventArgs e);
-}
+}

LibreHardwareMonitor/UI/MainForm.Designer.cs

@@ -64,6 +64,8 @@ namespace LibreHardwareMonitor.UI
             this.exitMenuItem = new System.Windows.Forms.ToolStripMenuItem();
             this.viewMenuItem = new System.Windows.Forms.ToolStripMenuItem();
             this.resetMinMaxMenuItem = new System.Windows.Forms.ToolStripMenuItem();
+            this.expandAllNodesMenuItem = new System.Windows.Forms.ToolStripMenuItem();
+            this.collpaseAllNodesMenuItem = new System.Windows.Forms.ToolStripMenuItem();
             this.resetPlotMenuItem = new System.Windows.Forms.ToolStripMenuItem();
             this.MenuItem3 = new System.Windows.Forms.ToolStripSeparator();
             this.hiddenMenuItem = new System.Windows.Forms.ToolStripMenuItem();
@@ -363,6 +365,8 @@ namespace LibreHardwareMonitor.UI
             //
             this.viewMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
             this.resetMinMaxMenuItem,
+            this.expandAllNodesMenuItem,
+            this.collpaseAllNodesMenuItem,
             this.resetPlotMenuItem,
             this.MenuItem3,
             this.hiddenMenuItem,
@@ -381,6 +385,20 @@ namespace LibreHardwareMonitor.UI
             this.resetMinMaxMenuItem.Text = "Reset Min/Max";
             this.resetMinMaxMenuItem.Click += new System.EventHandler(this.ResetMinMaxMenuItem_Click);
             //
+            // expandAllNodesMenuItem
+            //
+            this.expandAllNodesMenuItem.Name = "expandAllNodesMenuItem";
+            this.expandAllNodesMenuItem.Size = new System.Drawing.Size(188, 22);
+            this.expandAllNodesMenuItem.Text = "Expand All Nodes";
+            this.expandAllNodesMenuItem.Click += new System.EventHandler(this.ExpandAllNodes_Click);
+            //
+            // collpaseAllNodesMenuItem
+            //
+            this.collpaseAllNodesMenuItem.Name = "collpaseAllNodesMenuItem";
+            this.collpaseAllNodesMenuItem.Size = new System.Drawing.Size(188, 22);
+            this.collpaseAllNodesMenuItem.Text = "Collapse All Nodes";
+            this.collpaseAllNodesMenuItem.Click += new System.EventHandler(this.CollapsepAllNodes_Click);
+            //
             // resetPlotMenuItem
             //
             this.resetPlotMenuItem.Name = "resetPlotMenuItem";
@@ -1134,6 +1152,8 @@ namespace LibreHardwareMonitor.UI
         private ToolStripRadioButtonMenuItem fahrenheitMenuItem;
         private System.Windows.Forms.ToolStripSeparator MenuItem2;
         private System.Windows.Forms.ToolStripMenuItem resetMinMaxMenuItem;
+        private System.Windows.Forms.ToolStripMenuItem expandAllNodesMenuItem;
+        private System.Windows.Forms.ToolStripMenuItem collpaseAllNodesMenuItem;
         private System.Windows.Forms.ToolStripMenuItem resetPlotMenuItem;
         private System.Windows.Forms.ToolStripSeparator MenuItem3;
         private System.Windows.Forms.ToolStripMenuItem gadgetMenuItem;

LibreHardwareMonitor/UI/MainForm.cs

@@ -1239,6 +1239,16 @@ public sealed partial class MainForm : Form
         }));
     }
 
+    private void ExpandAllNodes_Click(object sender, EventArgs e)
+    {
+        treeView.ExpandAll();
+    }
+
+    private void CollapsepAllNodes_Click(object sender, EventArgs e)
+    {
+        treeView.CollapseAll();
+    }
+
     private void resetPlotMenuItem_Click(object sender, EventArgs e)
     {
         _computer.Accept(new SensorVisitor(delegate (ISensor sensorClick)