tools/pdf: display retina images on Emacs NS-port #1667

* Advice pdf-tools to display retina image on Mac
* Apply to other functions
* hotfix
* remove redundant advice

modules/tools/pdf/autoload/pdf.el

@@ -0,0 +1,111 @@
+;;; tools/pdf/autoload/pdf.el -*- lexical-binding: t; -*-
+;;;###autoload
+(defun *pdf-pdf-view-use-scaling-p ()
+  "Return t if scaling should be used."
+  (and (or (and (eq (framep-on-display) 'ns) (string-equal emacs-version "27.0.50"))
+           (memq (pdf-view-image-type)
+                 '(imagemagick image-io)))
+       pdf-view-use-scaling))
+;;;###autoload
+(defun *pdf-pdf-annot-show-annotation (a &optional highlight-p window)
+  "Make annotation A visible.
+
+Turn to A's page in WINDOW, and scroll it if necessary.
+
+If HIGHLIGHT-P is non-nil, visually distinguish annotation A from
+other annotations."
+
+  (save-selected-window
+    (when window (select-window window))
+    (pdf-util-assert-pdf-window)
+    (let* ((page (pdf-annot-get a 'page))
+           (size (pdf-view-image-size))
+           (width (car size)))
+      (unless (= page (pdf-view-current-page))
+        (pdf-view-goto-page page))
+      (let ((edges (pdf-annot-get-display-edges a)))
+        (when highlight-p
+          (pdf-view-display-image
+           (pdf-view-create-image
+               (pdf-cache-renderpage-highlight
+                page width
+                `("white" "steel blue" 0.35 ,@edges))
+             :map (pdf-view-apply-hotspot-functions
+                   window page size)
+             :width width)))
+        (pdf-util-scroll-to-edges
+         (pdf-util-scale-relative-to-pixel (car edges)))))))
+;;;###autoload
+(defun *pdf-pdf-isearch-hl-matches (current matches &optional occur-hack-p)
+  "Highlighting edges CURRENT and MATCHES."
+  (cl-check-type current pdf-isearch-match)
+  (cl-check-type matches (list-of pdf-isearch-match))
+  (cl-destructuring-bind (fg1 bg1 fg2 bg2)
+      (pdf-isearch-current-colors)
+    (let* ((width (car (pdf-view-image-size)))
+           (page (pdf-view-current-page))
+           (window (selected-window))
+           (buffer (current-buffer))
+           (tick (cl-incf pdf-isearch--hl-matches-tick))
+           (pdf-info-asynchronous
+            (lambda (status data)
+              (when (and (null status)
+                         (eq tick pdf-isearch--hl-matches-tick)
+                         (buffer-live-p buffer)
+                         (window-live-p window)
+                         (eq (window-buffer window)
+                             buffer))
+                (with-selected-window window
+                  (when (and (derived-mode-p 'pdf-view-mode)
+                             (or isearch-mode
+                                 occur-hack-p)
+                             (eq page (pdf-view-current-page)))
+                    (pdf-view-display-image
+                     (pdf-view-create-image data
+                       :width width))))))))
+      (pdf-info-renderpage-text-regions
+       page width t nil
+       `(,fg1 ,bg1 ,@(pdf-util-scale-pixel-to-relative
+                      current))
+       `(,fg2 ,bg2 ,@(pdf-util-scale-pixel-to-relative
+                      (apply 'append
+                             (remove current matches))))))))
+;;;###autoload
+(defun *pdf-pdf-util-frame-scale-factor ()
+  "Return the frame scale factor depending on the image type used for display.
+When `pdf-view-use-scaling' is non-nil and imagemagick or
+image-io are used as the image type for display, return the
+backing-scale-factor of the frame if available. If a
+backing-scale-factor attribute isn't available, return 2 if the
+frame's PPI is larger than 180. Otherwise, return 1."
+  (if (and pdf-view-use-scaling
+           (memq (pdf-view-image-type) '(imagemagick image-io))
+           (fboundp 'frame-monitor-attributes))
+      (or (cdr (assq 'backing-scale-factor (frame-monitor-attributes)))
+          (if (>= (pdf-util-frame-ppi) 180)
+              2
+            1))
+    (if (and (eq (framep-on-display) 'ns) (string-equal emacs-version "27.0.50"))
+        2
+      1)))
+;;;###autoload
+(defun *pdf-pdf-view-display-region (&optional region rectangle-p)
+  ;; TODO: write documentation!
+  (unless region
+    (pdf-view-assert-active-region)
+    (setq region pdf-view-active-region))
+  (let ((colors (pdf-util-face-colors
+                 (if rectangle-p 'pdf-view-rectangle 'pdf-view-region)
+                 (bound-and-true-p pdf-view-dark-minor-mode)))
+        (page (pdf-view-current-page))
+        (width (car (pdf-view-image-size))))
+    (pdf-view-display-image
+     (pdf-view-create-image
+         (if rectangle-p
+             (pdf-info-renderpage-highlight
+              page width nil
+              `(,(car colors) ,(cdr colors) 0.35 ,@region))
+           (pdf-info-renderpage-text-regions
+            page width nil nil
+            `(,(car colors) ,(cdr colors) ,@region)))
+       :width width))))

modules/tools/pdf/config.el

@@ -20,7 +20,15 @@
   (add-hook! 'pdf-view-mode-hook
     (add-hook 'kill-buffer-hook #'+pdf-cleanup-windows-h nil t))
 
-  (setq-default pdf-view-display-size 'fit-page)
+  (setq-default pdf-view-display-size 'fit-page
+                pdf-view-use-scaling t
+                pdf-view-use-imagemagick nil)
+
+  (advice-add 'pdf-annot-show-annotation :override #'*pdf-pdf-annot-show-annotation)
+  (advice-add 'pdf-isearch-hl-matches :override #'*pdf-pdf-isearch-hl-matches)
+  (advice-add 'pdf-util-frame-scale-factor :override #'*pdf-pdf-util-frame-scale-factor)
+  (advice-add 'pdf-view-display-region :override #'*pdf-pdf-view-display-region)
+  (advice-add 'pdf-view-use-scaling-p :override #'*pdf-pdf-view-use-scaling-p)
   ;; Turn off cua so copy works
   (add-hook! 'pdf-view-mode-hook (cua-mode 0))
   ;; Handle PDF-tools related popups better