From 3741435f1906ea31f84e35f8c5b9bc9f458ab75e Mon Sep 17 00:00:00 2001
From: L1Q <0xL1Q@ex.ua>
Date: Tue, 24 Oct 2017 05:31:02 +0300
Subject: [PATCH] Pan editor on resize

---
 .../Forms/RegionCaptureForm.cs                | 36 ++++++++++++++-----
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/ShareX.ScreenCaptureLib/Forms/RegionCaptureForm.cs b/ShareX.ScreenCaptureLib/Forms/RegionCaptureForm.cs
index 8b4e51805..3405ae6b6 100644
--- a/ShareX.ScreenCaptureLib/Forms/RegionCaptureForm.cs
+++ b/ShareX.ScreenCaptureLib/Forms/RegionCaptureForm.cs
@@ -57,6 +57,7 @@ public sealed class RegionCaptureForm : Form
         public bool IsAnnotated => ShapeManager != null && ShapeManager.IsAnnotated;
 
         public Point CurrentPosition { get; private set; }
+        public Size OldSize;
 
         public Color CurrentColor
         {
@@ -105,6 +106,7 @@ public RegionCaptureForm(RegionCaptureMode mode)
             Mode = mode;
 
             ScreenRectangle0Based = CaptureHelpers.GetScreenBounds0Based();
+            OldSize = ScreenRectangle0Based.Size;
             ImageRectangle = ScreenRectangle0Based;
 
             InitializeComponent();
@@ -288,11 +290,6 @@ private void OnMoved()
                 if (IsEditorMode && WindowState != lastWindowState)
                 {
                     lastWindowState = WindowState;
-
-                    if (WindowState == FormWindowState.Normal || WindowState == FormWindowState.Maximized)
-                    {
-                        CenterCanvas(false);
-                    }
                 }
 
                 if (IsAnnotationMode && ShapeManager.ToolbarCreated)
@@ -302,6 +299,21 @@ private void OnMoved()
             }
         }
 
+        private void UpdatePan()
+        {
+            Size NewSize = ScreenRectangle0Based.Size;
+            if (OldSize == NewSize)
+            {
+                return;
+            }
+
+            Point ResizeDelta = new Point((NewSize.Width - OldSize.Width) / 2, (NewSize.Height - OldSize.Height) / 2);
+
+            Pan(ResizeDelta);
+
+            OldSize = ScreenRectangle0Based.Size;
+        }
+
         public void SetDefaultCursor()
         {
             if (Cursor != defaultCursor)
@@ -320,6 +332,7 @@ private void RegionCaptureForm_Shown(object sender, EventArgs e)
         private void RegionCaptureForm_Resize(object sender, EventArgs e)
         {
             OnMoved();
+            UpdatePan();
         }
 
         private void RegionCaptureForm_LocationChanged(object sender, EventArgs e)
@@ -509,10 +522,7 @@ private new void Update()
 
             if (ShapeManager.IsPanning)
             {
-                ImageRectangle = ImageRectangle.LocationOffset(InputManager.MouseVelocity.X, InputManager.MouseVelocity.Y);
-                backgroundBrush.TranslateTransform(InputManager.MouseVelocity.X, InputManager.MouseVelocity.Y);
-
-                ShapeManager.MoveAll(InputManager.MouseVelocity);
+                Pan(InputManager.MouseVelocity);
             }
 
             borderDotPen.DashOffset = (float)timerStart.Elapsed.TotalSeconds * -15;
@@ -520,6 +530,14 @@ private new void Update()
             ShapeManager.Update();
         }
 
+        private void Pan(Point delta)
+        {
+            ImageRectangle = ImageRectangle.LocationOffset(delta.X, delta.Y);
+            backgroundBrush.TranslateTransform(delta.X, delta.Y);
+
+            ShapeManager.MoveAll(delta);
+        }
+
         protected override void OnPaintBackground(PaintEventArgs e)
         {
             //base.OnPaintBackground(e);