feat: Do not change cursor position on select_entry (#71)

* Do not change cursor position on select_entry

Consistent behavior with select_next_entry and select_prev_entry.

* Create focus_entry; selects entry and focuses

* Document focus_entry behavior

Author: pappasam

README.md

@@ -24,7 +24,7 @@ for any git rev.
 Install the plugin with your package manager of choice.
 
 ```vim
-" Plug 
+" Plug
 Plug 'sindrets/diffview.nvim'
 ```
 
@@ -70,7 +70,7 @@ require'diffview'.setup {
     -- The `view` bindings are active in the diff buffers, only when the current
     -- tabpage is a Diffview.
     view = {
-      ["<tab>"]      = cb("select_next_entry"),  -- Open the diff for the next file 
+      ["<tab>"]      = cb("select_next_entry"),  -- Open the diff for the next file
       ["<s-tab>"]    = cb("select_prev_entry"),  -- Open the diff for the previous file
       ["gf"]         = cb("goto_file"),          -- Open the file in a new split in previous tabpage
       ["<C-w><C-f>"] = cb("goto_file_split"),    -- Open the file in a new split
@@ -139,6 +139,15 @@ that only really make sense specifically in the file panel, such as
 invoked from the view, these will target the file currently open in the view
 rather than the file under the cursor in the file panel.
 
+### Available Unused Mappings
+
+This section documents key-mappable functions that are not mapped by default.
+
+- `focus_entry`
+  - Like `select_entry`, but open the diff for the selected entry while
+    focusing cursor on the current file. Available in both the file panel and
+    the history panel.
+
 ## File History
 
 ![file-history-multi](https://user-images.githubusercontent.com/2786478/131269782-f4184640-6d73-4226-b425-feccb5002dd0.png)

doc/diffview.txt

@@ -67,7 +67,7 @@ Example configuration with default settings:
         -- The `view` bindings are active in the diff buffers, only when the current
         -- tabpage is a Diffview.
         view = {
-          ["<tab>"]      = cb("select_next_entry"),  -- Open the diff for the next file 
+          ["<tab>"]      = cb("select_next_entry"),  -- Open the diff for the next file
           ["<s-tab>"]    = cb("select_prev_entry"),  -- Open the diff for the previous file
           ["gf"]         = cb("goto_file"),          -- Open the file in a new split in previous tabpage
           ["<C-w><C-f>"] = cb("goto_file_split"),    -- Open the file in a new split
@@ -131,6 +131,15 @@ enhanced_diff_hl                            *diffview-config-enhanced_diff_hl*
         in the left diff buffer will be highlighted as |hl-DiffDelete|, and
         the delete fill-chars will be highlighted more subtly.
 
+AVAILABLE UNUSED MAPPINGS                 *diffview-available-unused-mappings*
+
+This section documents key-mappable functions that are not mapped by default.
+
+focus_entry                                     *diffview-config-focus-entry*
+        Like select_entry, but open the diff for the selected entry while
+        focusing cursor on the current file. Available in both the file panel
+        and the history panel.
+
 LAYOUT                                                     *diffview-layout*
 
 The diff windows can be aligned either with a horizontal split or a vertical

lua/diffview/views/diff/listeners.lua

@@ -62,6 +62,14 @@ return function(view)
       view.panel:highlight_prev_file()
     end,
     select_entry = function()
+      if view.panel:is_open() then
+        local file = view.panel:get_file_at_cursor()
+        if file then
+          view:set_file(file, false)
+        end
+      end
+    end,
+    focus_entry = function()
       if view.panel:is_open() then
         local file = view.panel:get_file_at_cursor()
         if file then

lua/diffview/views/file_history/listeners.lua

@@ -89,6 +89,23 @@ return function(view)
       view.panel:highlight_prev_item()
     end,
     select_entry = function()
+      if view.panel:is_cur_win() then
+        local item = view.panel:get_item_at_cursor()
+        if item then
+          -- print(vim.inspect(item))
+          if item.files then
+            if view.panel.single_file then
+              view:set_file(item.files[1], false)
+            else
+              view.panel:toggle_entry_fold(item)
+            end
+          else
+            view:set_file(item, false)
+          end
+        end
+      end
+    end,
+    focus_entry = function()
       if view.panel:is_cur_win() then
         local item = view.panel:get_item_at_cursor()
         if item then