From 1e35ab3c5e499146d7ada78b2bb427af4e4236af Mon Sep 17 00:00:00 2001
From: "Mohammed Y. Alnajdi" <mohdnagfy@gmail.com>
Date: Sat, 3 Oct 2020 20:42:36 +0300
Subject: [PATCH] flexbox: initial attempt to support flex with rtl

---
 weasyprint/layout/flex.py | 74 +++++++++++++++++++++++++++------------
 1 file changed, 51 insertions(+), 23 deletions(-)

diff --git a/weasyprint/layout/flex.py b/weasyprint/layout/flex.py
index 3d610a50..5fc95dc6 100644
--- a/weasyprint/layout/flex.py
+++ b/weasyprint/layout/flex.py
@@ -650,33 +650,61 @@ def flex_layout(context, box, max_position_y, skip_stack, containing_block,
                         child.margin_bottom = free_space
             free_space = 0
 
-        if justify_content == 'flex-end':
-            position_axis += free_space
-        elif justify_content == 'center':
-            position_axis += free_space / 2
-        elif justify_content == 'space-around':
-            position_axis += free_space / len(line) / 2
-        elif justify_content == 'space-evenly':
-            position_axis += free_space / (len(line) + 1)
+        if box.style['direction'] == 'rtl':
+            if justify_content == 'flex-end':
+                position_axis -= free_space
+            elif justify_content == 'center':
+                position_axis -= free_space / 2
+            elif justify_content == 'space-around':
+                position_axis -= free_space / len(line) / 2
+            elif justify_content == 'space-evenly':
+                position_axis -= free_space / (len(line) - 1)
 
-        for i, child in line:
-            if axis == 'width':
-                child.position_x = position_axis
-                if justify_content == 'stretch':
-                    child.width += free_space / len(line)
-            else:
-                child.position_y = position_axis
-            position_axis += (
-                child.margin_width() if axis == 'width'
-                else child.margin_height())
-            if justify_content == 'space-around':
-                position_axis += free_space / len(line)
-            elif justify_content == 'space-between':
-                if len(line) > 1:
-                    position_axis += free_space / (len(line) - 1)
+            for i, child in line:
+                if axis == 'width':
+                    child.position_x = position_axis
+                    if justify_content == 'stretch':
+                        child.width -= free_space / len(line)
+                else:
+                    child.position_y = position_axis
+                position_axis -= (
+                    child.margin_width() if axis == 'width'
+                    else child.margin_height())
+                if justify_content == 'space-around':
+                    position_axis -= free_space / len(line)
+                elif justify_content == 'space-between':
+                    if len(line) > 1:
+                        position_axis -= free_space / (len(line) + 1)
+                elif justify_content == 'space-evenly':
+                    position_axis -= free_space / (len(line) - 1)
+        else:
+            if justify_content == 'flex-end':
+                position_axis += free_space
+            elif justify_content == 'center':
+                position_axis += free_space / 2
+            elif justify_content == 'space-around':
+                position_axis += free_space / len(line) / 2
             elif justify_content == 'space-evenly':
                 position_axis += free_space / (len(line) + 1)
 
+            for i, child in line:
+                if axis == 'width':
+                    child.position_x = position_axis
+                    if justify_content == 'stretch':
+                        child.width += free_space / len(line)
+                else:
+                    child.position_y = position_axis
+                position_axis += (
+                    child.margin_width() if axis == 'width'
+                    else child.margin_height())
+                if justify_content == 'space-around':
+                    position_axis += free_space / len(line)
+                elif justify_content == 'space-between':
+                    if len(line) > 1:
+                        position_axis += free_space / (len(line) - 1)
+                elif justify_content == 'space-evenly':
+                    position_axis += free_space / (len(line) + 1)
+
     # Step 13
     position_cross = (
         box.content_box_y() if cross == 'height'