[nongnu] elpa/better-jumper 8e82f33309 01/48: initial WIP implementation

[ELPA Syncer]

branch: elpa/better-jumper
commit 8e82f33309eb743a457ea9993da55ac428c7adab
Author: Bryan Gilbert <gilbertw1@gmail.com>
Commit: Bryan Gilbert <gilbertw1@gmail.com>

    initial WIP implementation
---
 Readme.md        |   3 +
 better-jumper.el | 300 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 303 insertions(+)

diff --git a/Readme.md b/Readme.md
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+++ b/Readme.md
@@ -0,0 +1,3 @@
+# better-jumper
+
+A configurable jump list implementation for Emacs
diff --git a/better-jumper.el b/better-jumper.el
new file mode 100644
index 0000000000..310da86138
--- /dev/null
+++ b/better-jumper.el
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+;;; better-jumper.el --- description -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;;; Code:
+
+(defgroup better-jumper nil
+  "Better jumper configuration options."
+  :prefix "better-jumper"
+  :group 'jump)
+
+(defcustom better-jumper-context 'window
+  "Determines the context that better jumper operates within."
+  :type '(choice (const :tag "Buffer" 'buffer)
+                 (other :tag "Window" 'window))
+  :group 'better-jumper)
+
+(defcustom better-jumper-isolate-perspectives t
+  "When non-nil, the jump commands respect buffer isolation provided by 
persp-mode perspectives."
+  :type 'boolean
+  :group 'better-jumper)
+
+(defcustom better-jumper-new-window-behavior 'copy-last-buffer
+  "Determines the behavior when a new window is created."
+  :type '(choice (const :tag "Empty jump list" empty)
+                 (const :tag "Copy last window" copy-last)
+                 (other :tag "Copy last window w/ buffer" copy-last-buffer))
+  :group 'better-jumper)
+
+(defcustom better-jumper-new-perspective-behavior 'empty
+  "Determines the behavior when a new window is created."
+  :type '(choice (const :tag "Copy last window" copy-last)
+                 (other :tag "Empty jump list" empty))
+  :group 'better-jumper)
+
+(defcustom better-jumper-max-length 100
+  "The maximum number of jumps to keep track of."
+  :type 'integer
+  :group 'better-jumper)
+
+(defcustom better-jumper-pre-jump-hook nil
+  "Hooks to run just before jumping to a location in the jump list."
+  :type 'hook
+  :group 'better-jumper)
+
+(defcustom better-jumper-post-jump-hook nil
+  "Hooks to run just after jumping to a location in the jump list."
+  :type 'hook
+  :group 'better-jumper)
+
+(defcustom better-jumper-ignored-file-patterns '("COMMIT_EDITMSG$" "TAGS$")
+  "A list of regexps used to exclude files from the jump list."
+  :type '(repeat string)
+  :group 'better-jumper)
+
+(defcustom better-jumper-use-evil-jump-advice t
+  "When non-nil, advice is added to add jumps whenever `evil-set-jump' is 
invoked."
+  :type 'boolean
+  :group 'better-jumper)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+
+(defvar better-jumper--jumping nil
+  "Flag inidicating jump in progress to prevent recording jumps in jump 
table.")
+
+(defvar better-jumper--buffer-targets "\\*\\(new\\|scratch\\)\\*"
+  "Regexp to match against `buffer-name' to determine whether it's a valid 
jump target.")
+
+(defvar better-jumper--jump-table (make-hash-table)
+  "Hashtable which stores all jumps on a per perspective/window basis.")
+
+(cl-defstruct better-jumper-jump-list-struct
+  ring
+  (idx -1))
+
+(defun better-jumper--persp-disable-window-config-update ()
+  "Set persp parameter to disable window config update."
+  (set-persp-parameter 'better-jumper-window-config-update-disabled t))
+
+(defun better-jumper--persp-enable-window-config-update ()
+  "Set persp parameter to disable window config update."
+  (set-persp-parameter 'better-jumper-window-config-update-disabled nil))
+
+(defun better-jumper--persp-window-config-update-disabled ()
+  "Indicate if window config update should be disabled for this persp."
+  (persp-parameter 'better-jumper-window-config-update-disabled ))
+
+(defun better-jumper--get-jump-table-perspective (&optional persp)
+  "Get jump table from PERSP or current perspective.
+This should be used when `better-jumper-isolate-perspectives' is non-nil."
+  (unless persp
+    (setq persp (get-current-persp)))
+  (let* ((jump-table (persp-parameter 'better-jumper-jump-table persp)))
+    (unless jump-table
+      (setq jump-table (make-hash-table))
+      (set-persp-parameter 'better-jumper-jump-table jump-table persp))
+    jump-table))
+
+(defun better-jumper--get-jump-table-global ()
+  "Get jump table stored in the variable `better-jumper--jump-table'."
+  better-jumper--jump-table)
+
+(defun better-jumper--get-jump-table ()
+  "Get jump table.
+The jump table is sourced either globally or from the current perspective
+depending on configuration."
+  (if better-jumper-isolate-perspectives
+      (better-jumper--get-jump-table-perspective)
+    (better-jumper--get-jump-table-global)))
+
+(defun better-jumper--set-window-struct (window struct)
+  (puthash window struct (better-jumper--get-jump-table)))
+
+(defun better-jumper--get-current-struct (&optional window)
+  "Get current jump struct for WINDOW.
+Creates and adds jump struct to perspective if missing. Uses current frame
+window if WINDOW parameter is missing."
+  (unless window
+    (setq window (frame-selected-window)))
+  (let* ((jump-table (better-jumper--get-jump-table))
+         (jump-struct (gethash window jump-table)))
+    (unless jump-struct
+      (setq jump-struct (make-better-jumper-jump-list-struct))
+      (puthash window jump-struct jump-table))
+    jump-struct))
+
+(defun better-jumper--get-jump-list (struct)
+  "Gets and potentially initialize jumps for STRUCT."
+  (let ((ring (better-jumper-jump-list-struct-ring struct)))
+    (unless ring
+      (setq ring (make-ring better-jumper-max-length))
+      (setf (better-jumper-jump-list-struct-ring struct) ring))
+    ring))
+
+(defun better-jumper--get-window-jump-list (&optional window)
+  "Gets jump list for WINDOW.
+Uses the current window if WINDOW is nil."
+  (let ((struct (better-jumper--get-current-struct window)))
+    (better-jumper--get-jump-list struct)))
+
+(defun better-jumper--jumps-jump (idx shift &optional window)
+  "Jump from position IDX using SHIFT on WINDOW or current window."
+  (let ((jump-list (better-jumper--get-window-jump-list window)))
+    (setq idx (+ idx shift))
+    (let* ((current-file-name (or (buffer-file-name) (buffer-name)))
+           (size (ring-length jump-list)))
+      (when (and (< idx size) (>= idx 0))
+        ;; actual jump
+        (run-hooks 'better-jumper-pre-jump-hook)
+        (let* ((place (ring-ref jump-list idx))
+               (pos (car place))
+               (file-name (cadr place)))
+          (setq better-jumper--jumping t)
+          (if (string-match-p better-jumper--buffer-targets file-name)
+              (switch-to-buffer file-name)
+            (find-file file-name))
+          (setq better-jumper--jumping nil)
+          (goto-char pos)
+          (setf (better-jumper-jump-list-struct-idx 
(better-jumper--get-current-struct window)) idx)
+          (run-hooks 'better-jumper-post-jump-hook))))))
+
+(defun better-jumper--jumps-push ()
+  "Pushes the current cursor/file position to the jump list."
+  (let* ((jump-list (better-jumper--get-window-jump-list))
+         (file-name (buffer-file-name))
+         (buffer-name (buffer-name))
+         (current-pos (point))
+         (first-pos nil)
+         (first-file-name nil)
+         (excluded nil))
+    (when (and (not file-name)
+                 (string-match-p better-jumper--buffer-targets buffer-name))
+        (setq file-name buffer-name))
+      (when file-name
+        (dolist (pattern better-jumper-ignored-file-patterns)
+          (when (string-match-p pattern file-name)
+            (setq excluded t)))
+        (unless excluded
+          (unless (ring-empty-p jump-list)
+            (setq first-pos (car (ring-ref jump-list 0)))
+            (setq first-file-name (car (cdr (ring-ref jump-list 0)))))
+          (unless (and (equal first-pos current-pos)
+                       (equal first-file-name file-name))
+            (ring-insert jump-list `(,current-pos ,file-name)))))))
+
+(defun better-jumper-set-jump (&optional pos)
+  "Set jump point at POS.
+POS defaults to point."
+  (unless (region-active-p)
+    (push-mark pos t))
+
+  (unless better-jumper--jumping
+    ;; clear out intermediary jumps when a new one is set
+    (let* ((struct (better-jumper--get-current-struct))
+           (jump-list (better-jumper--get-jump-list struct))
+           (idx (better-jumper-jump-list-struct-idx struct)))
+      (cl-loop repeat idx
+               do (ring-remove jump-list))
+      (setf (better-jumper-jump-list-struct-idx struct) -1))
+    (save-excursion
+      (when pos
+        (goto-char pos))
+      (better-jumper--jumps-push))))
+
+(defun better-jumper-jump-backward ()
+  "Jump backward to previous location in jump list."
+  (interactive)
+  (let* ((struct (better-jumper--get-current-struct))
+         (idx (better-jumper-jump-list-struct-idx struct)))
+    (when (= idx -1)
+      (setq idx 0)
+      (setf (better-jumper-jump-list-struct-idx struct) 0)
+      (better-jumper--jumps-push))
+    (better-jumper--jumps-jump idx 1)))
+
+(defun better-jumper-jump-forward ()
+  "Jump forward to previous location in jump list."
+  (interactive)
+  (let* ((struct (better-jumper--get-current-struct))
+         (idx (better-jumper-jump-list-struct-idx struct)))
+        (when (= idx -1)
+          (setq idx 0)
+          (setf (better-jumper-jump-list-struct-idx struct) 0)
+          (better-jumper--jumps-push))
+        (better-jumper--jumps-jump idx -1)))
+
+(defun better-jumper--window-configuration-hook (&rest args)
+  "Run on window configuration change (Ignore ARGS).
+Cleans up deleted windows and copies history to newly created windows."
+  (when (not (better-jumper--persp-window-config-update-disabled))
+    (let* ((jump-table (better-jumper--get-jump-table))
+           (window-list (window-list-1 nil nil t))
+           (existing-window (selected-window))
+           (new-window (previous-window)))
+      (when (and (not (eq existing-window new-window))
+                 (> (length window-list) 1))
+        (let* ((target-jump-struct (better-jumper--get-current-struct 
new-window))
+               (target-jump-list (better-jumper--get-jump-list 
target-jump-struct)))
+          (when (ring-empty-p target-jump-list)
+            (let* ((source-jump-struct (better-jumper--get-current-struct 
existing-window))
+                   (source-list (better-jumper--get-jump-list 
source-jump-struct)))
+              (setf (better-jumper-jump-list-struct-idx target-jump-struct) 
(better-jumper-jump-list-struct-idx source-jump-struct))
+              (setf (better-jumper-jump-list-struct-ring target-jump-struct) 
(ring-copy source-list))))))
+      ;; delete obsolete windows
+      (maphash (lambda (key val)
+                 (unless (member key window-list)
+                   (remhash key jump-table)))
+               jump-table))))
+
+(if better-jumper-use-evil-jump-advice
+    (defadvice evil-set-jump (before better-jumper activate)
+      (better-jumper-set-jump)))
+
+(defun better-jumper--save-perspective-jump-state ()
+  "Save the current window location state of the current perspective."
+  (let ((jump-state '())
+        (window-list (window-list-1)))
+    (dolist (window window-list)
+      (let* ((jump-struct (better-jumper--get-current-struct window))
+             (buf (buffer-name (window-buffer window)))
+             (pos (window-point window)))
+        (when buf
+          (push `(,buf ,pos ,jump-struct) jump-state))))
+    (set-persp-parameter 'better-jumper-persp-state jump-state)))
+
+(defun better-jumper--restore-perspective-jump-state ()
+  "Restore the jump list using saved window location state."
+  (let* ((jump-state (persp-parameter 'better-jumper-persp-state))
+         (window-list (window-list-1)))
+    (when jump-state
+      (dolist (window window-list)
+        (let* ((target-jump-list (better-jumper--get-window-jump-list window))
+               (buf (buffer-name (window-buffer window)))
+               (pos (window-point window)))
+          (when (and buf (ring-empty-p target-jump-list))
+            (let* ((matched-state (nth 2 (seq-find (lambda (e)
+                                                     (and (string= (nth 0 e) 
buf)
+                                                          (= (nth 1 e) pos))) 
jump-state))))
+              (unless matched-state
+                (setq matched-state (nth 2 (seq-find (lambda (e)
+                                                       (string= (nth 0 e) 
buf)) jump-state))))
+              (when matched-state
+                (better-jumper--set-window-struct window matched-state)))))))))
+
+(defun better-jumper--before-persp-deactivate (&rest args)
+  "Save jump state when a perspective is deactivated. Ignore ARGS."
+  (better-jumper--persp-disable-window-config-update)
+  (better-jumper--save-perspective-jump-state))
+
+(defun better-jumper--on-persp-activate (&rest args)
+  "Restore jump state when a perspective is activated. Ignore ARGS."
+  (better-jumper--restore-perspective-jump-state)
+  (better-jumper--persp-enable-window-config-update))
+
+(add-hook! 'persp-before-deactivate-functions 
#'better-jumper--before-persp-deactivate)
+(add-hook! 'persp-activated-functions #'better-jumper--on-persp-activate)
+(add-hook! 'persp-before-save-state-to-file-functions 
#'better-jumper--before-persp-deactivate)
+
+(provide 'better-jumper)
+;;; better-jumper.el ends here