From 6f384dd00a1a027b06f02b1958abf3566ea69e26 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 27 May 2017 23:30:45 +0530
Subject: [PATCH] Start work on implementing scrollIntoView for Safari

---
 src/pyj/read_book/cfi.pyj        |  4 ++--
 src/pyj/read_book/globals.pyj    | 28 ++++++++++++++++++++++++++++
 src/pyj/read_book/paged_mode.pyj |  4 +++-
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/pyj/read_book/cfi.pyj b/src/pyj/read_book/cfi.pyj
index dd61d28e8f..c70ed054aa 100644
--- a/src/pyj/read_book/cfi.pyj
+++ b/src/pyj/read_book/cfi.pyj
@@ -448,7 +448,7 @@ def scroll_to(cfi, callback, doc):  # {{{
         span = ndoc.createElement('span')
         span.setAttribute('style', 'border-width: 0; padding: 0; margin: 0')
         r.surroundContents(span)
-        span.scrollIntoView()
+        scroll_viewport.scroll_into_view(span)
         fn = def():
             # Remove the span and get the new position now that scrolling
             # has (hopefully) completed
@@ -482,7 +482,7 @@ def scroll_to(cfi, callback, doc):  # {{{
                 callback(x, y)
     else:
         node = point_.node
-        node.scrollIntoView()
+        scroll_viewport.scroll_into_view(node)
 
         fn = def():
             r = node.getBoundingClientRect()
diff --git a/src/pyj/read_book/globals.pyj b/src/pyj/read_book/globals.pyj
index dad4f011ed..c2ee261772 100644
--- a/src/pyj/read_book/globals.pyj
+++ b/src/pyj/read_book/globals.pyj
@@ -50,12 +50,20 @@ def flow_viewport_y():
 def flow_viewport_scroll_to(x, y):
     window.scrollTo(x, y)
 
+def flow_viewport_scroll_into_view(elem):
+    elem.scrollIntoView()
+
+def flow_reset_globals():
+    pass
+
 def paged_viewport_y():
     return 0
 
 scroll_viewport.x = flow_viewport_x
 scroll_viewport.y = flow_viewport_y
 scroll_viewport.scroll_to = flow_viewport_scroll_to
+scroll_viewport.scroll_into_view = flow_viewport_scroll_into_view
+scroll_viewport.reset_globals = flow_reset_globals
 
 if is_ios:
     window_width = def ():
@@ -80,6 +88,20 @@ if is_ios:
         if isNaN(ans):
             return 0
         return ans
+    paged_viewport_scroll_into_view = def(elem):
+        left = elem.offsetLeft
+        if left is None:
+            return  # element has display: none
+        elem.scrollIntoView()
+        window.scrollTo(0, 0)
+        p = elem.offsetParent
+        while p:
+            left += p.offsetLeft
+            p = p.offsetParent
+        # left -= window_width() // 2
+        paged_viewport_scroll_to(max(0, left), 0)
+    paged_reset_globals = def():
+        document.documentElement.style.transform = 'none'
 
 else:
     window_width = def():
@@ -88,6 +110,8 @@ else:
         return window.innerHeight
     paged_viewport_scroll_to = flow_viewport_scroll_to
     paged_viewport_x = flow_viewport_x
+    paged_viewport_scroll_into_view = flow_viewport_scroll_into_view
+    paged_reset_globals = flow_reset_globals
 
 scroll_viewport.width = window_width
 scroll_viewport.height = window_height
@@ -103,10 +127,14 @@ def set_layout_mode(val):
         scroll_viewport.x = flow_viewport_x
         scroll_viewport.y = flow_viewport_y
         scroll_viewport.scroll_to = flow_viewport_scroll_to
+        scroll_viewport.scroll_into_view = flow_viewport_scroll_into_view
+        scroll_viewport.reset_globals = flow_reset_globals
     else:
         scroll_viewport.x = paged_viewport_x
         scroll_viewport.y = paged_viewport_y
         scroll_viewport.scroll_to = paged_viewport_scroll_to
+        scroll_viewport.scroll_into_view = paged_viewport_scroll_into_view
+        scroll_viewport.reset_globals = paged_reset_globals
 
 def current_spine_item():
     return current_spine_item.value
diff --git a/src/pyj/read_book/paged_mode.pyj b/src/pyj/read_book/paged_mode.pyj
index 77fdfaeb48..5daa438a5b 100644
--- a/src/pyj/read_book/paged_mode.pyj
+++ b/src/pyj/read_book/paged_mode.pyj
@@ -54,6 +54,7 @@ is_full_screen_layout = False
 
 def reset_paged_mode_globals():
     nonlocal _in_paged_mode, col_width, col_and_gap, screen_height, gap, screen_width, is_full_screen_layout, cols_per_screen
+    scroll_viewport.reset_globals()
     col_width = screen_width = screen_height = cols_per_screen = gap = col_and_gap = 0
     is_full_screen_layout = _in_paged_mode = False
 
@@ -339,7 +340,8 @@ def jump_to_anchor(name):
     scroll_to_elem(elem)
 
 def scroll_to_elem(elem):
-    elem.scrollIntoView()
+    scroll_viewport.scroll_into_view(elem)
+
     if in_paged_mode:
         # Ensure we are scrolled to the column containing elem