X-Git-Url: https://jasonwoof.com/gitweb/?a=blobdiff_plain;f=editor.coffee;h=a7c3c660249574a0e75bc045beda7514ebf51f5f;hb=90fd4346459ebd1d895047622880a5d78ae419d2;hp=a02e278a6d922abcb56219c85bda73a3791203fb;hpb=6b36467240e6f8dd43d7a82c0ab8c0a54cd28c96;p=peach-html5-editor.git

diff --git a/editor.coffee b/editor.coffee
index a02e278..a7c3c66 100644
--- a/editor.coffee
+++ b/editor.coffee
@@ -955,6 +955,7 @@ class PeachHTML5Editor
 				@on_page_up_key e
 				return false
 			when KEY_PAGE_DOWN
+				@on_page_down_key e
 				return false
 			when KEY_TAB
 				return false
@@ -1076,47 +1077,81 @@ class PeachHTML5Editor
 				@kill_cursor()
 		return
 	on_page_up_key: (e) ->
+		if @cursor?
+			screen_y = @cursor.y - @wrap2.scrollTop
 		scroll_amount = @wrap2_height - breathing_room
-		# scroll up a page
 		@wrap2.scrollTop = Math.max 0, @wrap2.scrollTop - scroll_amount
-		# note: if cursor innacuracy causes it no not be within new scroll,
-		# @move_cursor will adjust the scroll a bit.
 		if @cursor?
-			# move cursor up approximately scroll_amount
-			was = @cursor
-			y_target = @cursor.y - scroll_amount
-			y_min = Math.min y_target, @wrap2.scrollTop
-			y_max = Math.min y_target, @wrap2.scrollTop - scroll_amount
-			y_target = Math.min y_target, y_max
-			y_target = Math.max y_target, y_min
-			loop
-				cur = find_up_cursor_position @tree, was, @cursor_ideal_x
-				break unless cur?
-				break if cur.y <= y_target
-				was = cur
-			if was is @cursor
-				if cur?
-					new_cursor = cur
-				else
-					# should this move the cursor to the beginning of the line?
-					new_cursor = null
-			else
-				if cur?
-					# both valid, pick best
-					if cur.y < y_min
-						new_cursor = was
-					else if was.y > 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
+			@move_cursor_into_view screen_y + @wrap2.scrollTop
+	on_page_down_key: (e) ->
+		if @cursor?
+			screen_y = @cursor.y - @wrap2.scrollTop
+		scroll_amount = @wrap2_height - breathing_room
+		lowest_scrollpos = @wrap2.scrollHeight - @wrap2_height
+		if @wrap2.scrollTop is lowest_scrollpos # already at bottom
+			return unless @cursor?
+			# move cursor to bottom
+			new_cursor = last_cursor_position @tree
 			if new_cursor?
-				saved_ideal_x = @cursor_ideal_x
-				@move_cursor new_cursor
-				@cursor_ideal_x = saved_ideal_x
+				if new_cursor.n isnt @cursor.n or new_cursor.i isnt @cursor.i
+					@move_cursor new_cursor
+			return
+		@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