X-Git-Url: https://jasonwoof.com/gitweb/?a=blobdiff_plain;f=editor.coffee;h=a0bd0a41d48864e6120bf7c2bfa90d4b56de99b8;hb=5de51db974972ef00b21121b7472075c0222b551;hp=8367d09b799835b528942d687b0c141fcff76e42;hpb=8e715e94e59e5bd05fea8e073de2750df2be1f8f;p=peach-html5-editor.git

diff --git a/editor.coffee b/editor.coffee
index 8367d09..a0bd0a4 100644
--- a/editor.coffee
+++ b/editor.coffee
@@ -16,6 +16,7 @@
 
 # SETTINGS
 overlay_padding = 10
+breathing_room = 30 # minimum pixels above/below cursor
 
 timeout = (ms, cb) -> return setTimeout cb, ms
 next_frame = (cb) ->
@@ -951,8 +952,10 @@ class PeachHTML5Editor
 			when KEY_INSERT
 				return false
 			when KEY_PAGE_UP
+				@on_page_up_key e
 				return false
 			when KEY_PAGE_DOWN
+				@on_page_down_key e
 				return false
 			when KEY_TAB
 				return false
@@ -1073,6 +1076,89 @@ class PeachHTML5Editor
 			else
 				@kill_cursor()
 		return
+	on_page_up_key: (e) ->
+		if @wrap2.scrollTop is 0
+			return unless @cursor?
+			new_cursor = first_cursor_position @tree
+			if new_cursor?
+				if new_cursor.n isnt @cursor.n or new_cursor.i isnt @cursor.i
+					@move_cursor new_cursor
+			return
+		if @cursor?
+			screen_y = @cursor.y - @wrap2.scrollTop
+		scroll_amount = @wrap2_height - breathing_room
+		@wrap2.scrollTop = Math.max 0, @wrap2.scrollTop - scroll_amount
+		if @cursor?
+			@move_cursor_into_view screen_y + @wrap2.scrollTop
+	on_page_down_key: (e) ->
+		lowest_scrollpos = @wrap2.scrollHeight - @wrap2_height
+		if @wrap2.scrollTop is lowest_scrollpos
+			return unless @cursor?
+			new_cursor = last_cursor_position @tree
+			if new_cursor?
+				if new_cursor.n isnt @cursor.n or new_cursor.i isnt @cursor.i
+					@move_cursor new_cursor
+			return
+		if @cursor?
+			screen_y = @cursor.y - @wrap2.scrollTop
+		scroll_amount = @wrap2_height - breathing_room
+		@wrap2.scrollTop = Math.min lowest_scrollpos, @wrap2.scrollTop + scroll_amount
+		if @cursor?
+			@move_cursor_into_view screen_y + @wrap2.scrollTop
+		return
+	move_cursor_into_view: (y_target) ->
+		return if y_target is @cursor.y
+		was = @cursor
+		y_min = @wrap2.scrollTop
+		unless @wrap2.scrollTop is 0
+			y_min += breathing_room
+		y_max = @wrap2.scrollTop + @wrap2_height
+		unless @wrap2.scrollTop is @wrap2.scrollHeight - @wrap2_height # downmost
+			y_max -= breathing_room
+		y_target = Math.min y_target, y_max
+		y_target = Math.max y_target, y_min
+		if y_target < @cursor.y
+			finder = find_up_cursor_position
+			far_enough = (cur, target_y) ->
+				return cur.y + cur.h <= target_y
+		else
+			finder = find_down_cursor_position
+			far_enough = (cur, y_target) ->
+				return cur.y >= y_target
+		loop
+			cur = finder @tree, was, @cursor_ideal_x
+			break unless cur?
+			break if far_enough cur, y_target
+			was = cur
+		if was is @cursor
+			was = null
+		if was?
+			if was.y + was.h > y_max
+				was = null
+			else if was.y < y_min
+				was = null
+		if cur?
+			if cur.y + cur.h > y_max
+				cur = null
+			else if cur.y < y_min
+				cur = null
+		if cur? and was?
+			# both valid, pick best
+			if cur.y < y_min
+				new_cursor = was
+			else if was.y + was.h > y_max
+				new_cursor = cur
+			else if cur.y - y_target < y_target - was.y
+				new_cursor = cur
+			else
+				new_cursor = was
+		else
+			new_cursor = was ? cur
+		if new_cursor?
+			saved_ideal_x = @cursor_ideal_x
+			@move_cursor new_cursor
+			@cursor_ideal_x = saved_ideal_x
+		return
 	clear_dom: -> # remove all the editable content (and cursor, overlays, etc)
 		while @idoc.body.childNodes.length
 			@idoc.body.removeChild @idoc.body.childNodes[0]
@@ -1234,21 +1320,20 @@ class PeachHTML5Editor
 		@annotate cursor.n
 		@scroll_into_view cursor.y, height
 	scroll_into_view: (y, h = 0) ->
-		closest = 30 # setting: smallest pixels from top/bottom of screet that's OK
 		y += overlay_padding # convert units from @idoc to @wrap2
 		# very top of document
-		if y <= closest
+		if y <= breathing_room
 			@wrap2.scrollTop = 0
 			return
 		# very bottom of document
-		if y + h >= @wrap2.scrollHeight - closest
+		if y + h >= @wrap2.scrollHeight - breathing_room
 			@wrap2.scrollTop = @wrap2.scrollHeight - @wrap2_height
 			return
 		# The most scrolled up (lowest value for scrollTop) that would be OK
-		upmost = y + h + closest - @wrap2_height
+		upmost = y + h + breathing_room - @wrap2_height
 		upmost = Math.max(upmost, 0)
 		# the most scrolled down (highest value for scrollTop) that would be OK
-		downmost = y - closest
+		downmost = y - breathing_room
 		downmost = Math.min(downmost, @wrap2.scrollHeight - @wrap2_height)
 		if upmost > downmost # means h is too big to fit
 			# scroll so top is visible