support for displaying images in webview

.claude/rules/frontend.md

@@ -20,7 +20,7 @@ Frontends subclass `implementation` and implement `lem-if:*` generics.
 (lem-if:set-view-pos impl view x y)
 
 ;; Rendering
-(lem-if:render-line impl view x y objects height)
+(lem-if:render-row impl view row)          ; ROW is a laid-out lem-core/display:row
 (lem-if:clear-to-end-of-window impl view y)
 ```
 

extensions/pixel-demo/pixel-demo.lisp

@@ -64,8 +64,8 @@
 (defun animation-step ()
   "Perform one animation step."
   (when (and *demo-window* (eq *demo-mode* :animate))
-    (let* ((char-width (lem-if:get-char-width (implementation)))
-           (char-height (lem-if:get-char-height (implementation)))
+    (let* ((char-width (lem-if:cell-width (implementation)))
+           (char-height (lem-if:cell-height (implementation)))
            (display-width (* (display-width) char-width))
            (display-height (* (display-height) char-height))
            (win-width (or (floating-window-pixel-width *demo-window*)
@@ -177,8 +177,8 @@ A floating window follows your mouse cursor at pixel precision."
   "Update coordinate debug display."
   (when (and *demo-window* (eq *demo-mode* :debug))
     (let* ((mouse-event (lem-core::last-mouse-event))
-           (char-width (lem-if:get-char-width (implementation)))
-           (char-height (lem-if:get-char-height (implementation))))
+           (char-width (lem-if:cell-width (implementation)))
+           (char-height (lem-if:cell-height (implementation))))
       (multiple-value-bind (win-px win-py win-pw win-ph)
           (floating-window-pixel-bounds *demo-window*)
         (let ((content
@@ -230,8 +230,8 @@ Shows real-time pixel and character coordinate information."
 (defun compare-animation-step ()
   "Animate both windows for comparison."
   (when (eq *demo-mode* :compare)
-    (let* ((char-width (lem-if:get-char-width (implementation)))
-           (char-height (lem-if:get-char-height (implementation)))
+    (let* ((char-width (lem-if:cell-width (implementation)))
+           (char-height (lem-if:cell-height (implementation)))
            (display-width (* (display-width) char-width))
            (display-height (* (display-height) char-height))
            (win-width (* 20 char-width)))

frontends/fake-interface/fake-interface.lisp

@@ -97,24 +97,22 @@
 (defmethod lem-if:object-height ((implementation fake-interface) object)
   1)
 
-(defmethod lem-if:render-line ((implementation fake-interface) view x y objects height)
+(defmethod lem-if:render-row ((implementation fake-interface) view row)
   nil)
 
 (defmethod lem-if:clear-to-end-of-window ((implementation fake-interface) view y)
   nil)
 
-(defmethod lem-if:get-char-width ((implementation fake-interface))
+(defmethod lem-if:cell-width ((implementation fake-interface))
   1)
 
-(defmethod lem-if:get-char-height ((implementation fake-interface))
+(defmethod lem-if:cell-height ((implementation fake-interface))
   1)
 
-(defmethod lem-if:render-line-on-modeline ((implementation fake-interface)
-                                           view
-                                           left-objects
-                                           right-objects
-                                           default-attribute
-                                           height)
+(defmethod lem-if:render-modeline-row ((implementation fake-interface)
+                                       view
+                                       row
+                                       default-attribute)
   nil)
 
 (defmacro with-fake-interface (() &body body)

frontends/ncurses/lem-ncurses.asd

@@ -12,7 +12,6 @@
                (:file "style")
                (:file "key")
                (:file "attribute")
-               (:file "drawing-object")
                (:file "view")
                (:file "render")
                (:file "input")

frontends/ncurses/ncurses.lisp

@@ -85,28 +85,31 @@
 (defmethod lem-if:view-height ((implementation ncurses) view)
   (lem-ncurses/view:view-height view))
 
-(defmethod lem-if:render-line ((implementation ncurses)
-                               view x y objects height)
-  (lem-ncurses/render:render-line view x y objects))
+(defmethod lem-if:render-row ((implementation ncurses) view row)
+  (lem-ncurses/render:render-row view row))
 
-(defmethod lem-if:render-line-on-modeline ((implementation ncurses)
-                                           view
-                                           left-objects
-                                           right-objects
-                                           default-attribute
-                                           height)
-  (lem-ncurses/render:render-line-on-modeline view left-objects right-objects default-attribute))
+(defmethod lem-if:render-modeline-row ((implementation ncurses) view row default-attribute)
+  (lem-ncurses/render:render-modeline-row view row default-attribute))
 
-(defmethod lem-if:object-width ((implementation ncurses) drawing-object)
-  (lem-ncurses/drawing-object:object-width drawing-object))
+(defmethod lem-if:object-width ((implementation ncurses)
+                                (drawing-object lem-core/display:image-object))
+  0)
 
-(defmethod lem-if:object-height ((implementation ncurses) drawing-object)
-  (lem-ncurses/drawing-object:object-height drawing-object))
+(defmethod lem-if:object-height ((implementation ncurses)
+                                 (drawing-object lem-core/display:image-object))
+  1)
+
+(defmethod lem-if:object-ascent ((implementation ncurses)
+                                 (drawing-object lem-core/display:image-object))
+  1)
 
 (defmethod lem-if:clear-to-end-of-window ((implementation ncurses) view y)
   (lem-ncurses/render:clear-to-end-of-window view y))
 
-(defmethod lem-if:get-char-width ((implementation ncurses))
+(defmethod lem-if:cell-width ((implementation ncurses))
+  1)
+
+(defmethod lem-if:cell-height ((implementation ncurses))
   1)
 
 ;; for mouse control

frontends/ncurses/render.lisp

@@ -1,8 +1,8 @@
 (defpackage :lem-ncurses/render
   (:use :cl
         :lem-core/display)
-  (:export :render-line
-           :render-line-on-modeline
+  (:export :render-row
+           :render-modeline-row
            :clear-to-end-of-window))
 (in-package :lem-ncurses/render)
 
@@ -37,17 +37,6 @@
    " "
    (lem:make-attribute :foreground (lem:color-to-hex-string (eol-cursor-object-color object)))))
 
-(defmethod draw-object ((object extend-to-eol-object) x y view scrwin)
-  (let ((width (lem-if:view-width (lem:implementation) view)))
-    (when (< x width)
-      (print-string
-       scrwin
-       x
-       y
-       (make-string (- width x) :initial-element #\space)
-       (lem:make-attribute :background
-                           (lem:color-to-hex-string (extend-to-eol-object-color object)))))))
-
 (defmethod draw-object ((object line-end-object) x y view scrwin)
   (let ((string (text-object-string object))
         (attribute (text-object-attribute object)))
@@ -61,40 +50,43 @@
 (defmethod draw-object ((object image-object) x y view scrwin)
   (values))
 
-(defun render-line-from-behind (view y objects scrwin)
-  (loop :with current-x := (lem-if:view-width (lem:implementation) view)
-        :for object :in objects
-        :do (decf current-x (lem-ncurses/drawing-object:object-width object))
-            (draw-object object current-x y view scrwin)))
-
 (defun clear-line (view x y)
   (charms/ll:wmove (lem-ncurses/view:view-scrwin view) y x)
   (charms/ll:wclrtoeol (lem-ncurses/view:view-scrwin view)))
 
-(defun %render-line (view x y objects scrwin)
-  (loop :for object :in objects
-        :do (draw-object object x y view scrwin)
-            (incf x (lem-ncurses/drawing-object:object-width object))))
+(defun draw-row (view row scrwin)
+  "Draw ROW's background fill, then everything placed on it.
+The fill is spaces carrying the background color, since a terminal cell only takes a color by
+having a character written into it."
+  (let ((width (lem-if:view-width (lem:implementation) view)))
+    (when (and (row-fill-color row)
+               (< (row-fill-x row) width))
+      (print-string scrwin
+                    (row-fill-x row)
+                    (row-top row)
+                    (make-string (- width (row-fill-x row)) :initial-element #\space)
+                    (lem:make-attribute :background
+                                        (lem:color-to-hex-string (row-fill-color row))))))
+  (loop :for placement :in (row-placements row)
+        :do (draw-object (placement-object placement)
+                         (placement-x placement)
+                         (placement-top placement)
+                         view
+                         scrwin)))
 
-(defun render-line (view x y objects)
-  (clear-line view x y)
-  (%render-line view x y objects (lem-ncurses/view:view-scrwin view)))
+(defun render-row (view row)
+  (clear-line view 0 (row-top row))
+  (draw-row view row (lem-ncurses/view:view-scrwin view)))
 
-(defun render-line-on-modeline (view
-                                left-objects
-                                right-objects
-                                default-attribute)
+(defun render-modeline-row (view row default-attribute)
+  ;; the modeline gets its own curses window, so its row (laid out at top 0) needs no translation.
   (print-string (lem-ncurses/view:view-modeline-scrwin view)
                 0
-                0
+                (row-top row)
                 (make-string (lem-ncurses/view:view-width view)
                              :initial-element #\space)
                 default-attribute)
-  (%render-line view 0 0 left-objects (lem-ncurses/view:view-modeline-scrwin view))
-  (render-line-from-behind view
-                           0
-                           right-objects
-                           (lem-ncurses/view:view-modeline-scrwin view)))
+  (draw-row view row (lem-ncurses/view:view-modeline-scrwin view)))
 
 (defun clear-to-end-of-window (view y)
   (let ((win (lem-ncurses/view:view-scrwin view)))

frontends/ncurses/view.lisp

@@ -16,8 +16,8 @@
            :set-view-pos
            :redraw-view-after
            :redraw-display-after
-           :render-line
-           :render-line-on-modeline
+           :render-row
+           :render-modeline-row
            :clear-to-end-of-window
            :update-display
            :set-last-print-cursor))

frontends/sdl2/display.lisp

@@ -112,7 +112,7 @@ Retina to a 1x display).")
                  :documentation
                  "Pre-allocated SDL_Rect reused across all render calls to
 avoid heap-allocating a new rect + Lisp wrapper on every draw-rect,
-fill-to-end-of-line, render-texture, etc.  Mutated in-place by
+fill-row, render-texture, etc.  Mutated in-place by
 `call-with-scratch-rect' / `with-scratch-rect'; do not rely on its
 contents outside the dynamic extent of that call.")))