feature: drag a branch onto another branch to open a context menu with actions between them

src/Models/Remote.cs

@@ -146,5 +146,77 @@ public bool TryGetCreatePullRequestURL(out string url, string mergeBranch)
 
             return false;
         }
+
+        /// <summary>
+        ///     Builds the URL to create a pull request on this remote that merges `sourceBranch` into `targetBranch`.
+        ///     When `sourceRemote` is another remote (e.g. a fork), only GitHub is supported.
+        /// </summary>
+        public bool TryGetCreatePullRequestURL(out string url, string sourceBranch, string targetBranch, Remote sourceRemote)
+        {
+            url = null;
+
+            if (!TryGetVisitURL(out var baseURL))
+                return false;
+
+            var host = new Uri(baseURL).Host;
+            var source = HttpUtility.UrlEncode(sourceBranch);
+            var target = HttpUtility.UrlEncode(targetBranch);
+
+            if (sourceRemote != null && sourceRemote != this)
+            {
+                if (!host.Contains("github.com", StringComparison.Ordinal) || !sourceRemote.TryGetVisitURL(out var sourceURL))
+                    return false;
+
+                var sourceURI = new Uri(sourceURL);
+                if (!sourceURI.Host.Equals(host, StringComparison.Ordinal))
+                    return false;
+
+                var segments = sourceURI.AbsolutePath.Split('/', StringSplitOptions.RemoveEmptyEntries);
+                if (segments.Length < 2)
+                    return false;
+
+                url = $"{baseURL}/compare/{target}...{HttpUtility.UrlEncode(segments[0])}:{HttpUtility.UrlEncode(segments[1])}:{source}?expand=1";
+                return true;
+            }
+
+            if (host.Contains("github.com", StringComparison.Ordinal))
+            {
+                url = $"{baseURL}/compare/{target}...{source}?expand=1";
+                return true;
+            }
+
+            if (host.Contains("gitlab", StringComparison.Ordinal))
+            {
+                url = $"{baseURL}/-/merge_requests/new?merge_request%5Bsource_branch%5D={source}&merge_request%5Btarget_branch%5D={target}";
+                return true;
+            }
+
+            if (host.Equals("gitee.com", StringComparison.Ordinal))
+            {
+                url = $"{baseURL}/pulls/new?source={source}&target={target}";
+                return true;
+            }
+
+            if (host.Equals("bitbucket.org", StringComparison.Ordinal))
+            {
+                url = $"{baseURL}/pull-requests/new?source={source}&dest={target}";
+                return true;
+            }
+
+            if (host.Equals("gitea.org", StringComparison.Ordinal))
+            {
+                url = $"{baseURL}/compare/{target}...{source}";
+                return true;
+            }
+
+            if (host.Contains("azure.com", StringComparison.Ordinal) ||
+                host.Contains("visualstudio.com", StringComparison.Ordinal))
+            {
+                url = $"{baseURL}/pullrequestcreate?sourceRef={source}&targetRef={target}";
+                return true;
+            }
+
+            return false;
+        }
     }
 }

src/Resources/Locales/en_US.axaml

@@ -61,13 +61,15 @@
   <x:String x:Key="Text.Blame.TypeNotSupported" xml:space="preserve">BLAME ON THIS FILE IS NOT SUPPORTED!!!</x:String>
   <x:String x:Key="Text.BranchCM.Checkout" xml:space="preserve">Checkout ${0}$...</x:String>
   <x:String x:Key="Text.BranchCM.CheckoutAsWorktree" xml:space="preserve">Checkout ${0}$ as worktree...</x:String>
+  <x:String x:Key="Text.BranchCM.CompareBranches" xml:space="preserve">Compare ${0}$ with ${1}$</x:String>
   <x:String x:Key="Text.BranchCM.CompareTwo" xml:space="preserve">Compare selected 2 branches</x:String>
   <x:String x:Key="Text.BranchCM.CompareWith" xml:space="preserve">Compare with...</x:String>
   <x:String x:Key="Text.BranchCM.CompareWithHead" xml:space="preserve">Compare with HEAD</x:String>
   <x:String x:Key="Text.BranchCM.CompareWithSpecial" xml:space="preserve">Compare with ${0}$</x:String>
   <x:String x:Key="Text.BranchCM.CopyName" xml:space="preserve">Copy Branch Name</x:String>
   <x:String x:Key="Text.BranchCM.CreatePR" xml:space="preserve">Create PR...</x:String>
   <x:String x:Key="Text.BranchCM.CreatePRForUpstream" xml:space="preserve">Create PR for upstream ${0}$...</x:String>
+  <x:String x:Key="Text.BranchCM.CreatePRFromTo" xml:space="preserve">Create PR from ${0}$ into ${1}$...</x:String>
   <x:String x:Key="Text.BranchCM.CustomAction" xml:space="preserve">Custom Action</x:String>
   <x:String x:Key="Text.BranchCM.Delete" xml:space="preserve">Delete ${0}$...</x:String>
   <x:String x:Key="Text.BranchCM.DeleteMultiBranches" xml:space="preserve">Delete selected {0} branches...</x:String>

src/ViewModels/BranchTreeNode.cs

@@ -34,6 +34,18 @@ public CornerRadius CornerRadius
             set => SetProperty(ref _cornerRadius, value);
         }
 
+        public bool IsDragSource
+        {
+            get => _isDragSource;
+            set => SetProperty(ref _isDragSource, value);
+        }
+
+        public bool IsDropTarget
+        {
+            get => _isDropTarget;
+            set => SetProperty(ref _isDropTarget, value);
+        }
+
         public bool IsBranch
         {
             get => Backend is Models.Branch;
@@ -57,6 +69,8 @@ public string BranchesCount
         private Models.FilterMode _filterMode = Models.FilterMode.None;
         private bool _isExpanded = false;
         private CornerRadius _cornerRadius = new CornerRadius(4);
+        private bool _isDragSource = false;
+        private bool _isDropTarget = false;
 
         public class Builder
         {