idee-navigation.el

;; idee-navigation.el --- Navigation Utilities

;; Copyright (C) 2018 Ioannis Canellos

;; Licensed under the Apache License, Version 2.0 (the "License");
;; you may not use this file except in compliance with the License.
;; You may obtain a copy of the License at

;;       http://www.apache.org/licenses/LICENSE-2.0

;;Unless required by applicable law or agreed to in writing, software
;;distributed under the License is distributed on an "AS IS" BASIS,
;;WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
;;See the License for the specific language governing permissions and
;;limitations under the License.

;; Author: Ioannis Canellos

;;; Commentary:

;;; Code:

(require 'idee-vars)

;;
;; State
;;

(cl-defstruct idee/buffer-point
  buffer
  line
  column)

(defvar idee/back-stack ())
(defvar idee/forward-stack ())
(defvar ignore-current-buffer nil)

;;
;; Functions
;;
;;;###autoload
(defun idee/back-push()
  "Push the current point to the back stack."
  (interactive)
  (if ignore-current-buffer
      (setq ignore-current-buffer nil)
    (setq idee/back-stack (cons (make-idee/buffer-point :buffer (current-buffer) :line (line-number-at-pos (point)) :column (current-column)) idee/back-stack))))

;;;###autoload
(defun idee/back-pop()
  "Pop the back stack."
  (interactive)
  (let ((p (car idee/back-stack)))
    (setq idee/back-stack (cdr idee/back-stack))
    p))

;;;###autoload
(defun idee/forward-push()
  "Push the current point to the forward stack."
  (interactive)
  (if ignore-current-buffer
      (setq ignore-current-buffer nil)
    (setq idee/forward-stack (cons (make-idee/buffer-point :buffer (current-buffer) :line (line-number-at-pos (point)) :column (current-column)) idee/back-stack))))

;;;###autoload
(defun idee/forward-pop()
  "Pop the forward stack."
  (interactive)
  (let ((p (car idee/forward-stack)))
    (setq idee/forward-stack (cdr idee/forward-stack))
    p))

;;;###autoload
(defun idee/forget-current-buffer()
  "Remove references to the current buffer from all navigation stacks."
  (interactive)
  (let ((c (current-buffer)) (b (car idee/back-stack)) (f (car idee/forward-stack)))
    (if (and b (equal c (idee/buffer-point-buffer b))) (idee/back-pop))
    (if (and f (equal c (idee/buffer-point-buffer f))) (idee/forward-pop))
    )
  (setq ignore-current-buffer t))


;;;###autoload
(defun idee/jump-back()
  "Jump back."
  (interactive)
  (let ((p (idee/back-pop)))
    (if p (progn
            (idee/forward-push)
            (switch-to-buffer (idee/buffer-point-buffer p))
            (goto-char (point-min))
            (forward-line (- (idee/buffer-point-line p) 1))
            (move-to-column (idee/buffer-point-column p))
            (point)))))

;;;###autoload
(defun idee/jump-forward()
  "Jump forward."
  (interactive)
  (let ((p (idee/forward-pop)))
    (if p (progn
            (idee/back-push)
            (switch-to-buffer (idee/buffer-point-buffer p))
            (goto-char (point-min))
            (forward-line (- (idee/buffer-point-line p) 1))
            (move-to-column (idee/buffer-point-column p))
            (point)))))

(provide 'idee-navigation)
;; idee-navigation.el ends here