From 035ad1cd2e3e6a28e145723a441339f4a8cafdd0 Mon Sep 17 00:00:00 2001
From: Ali Tavakoli <eng.tavakoli110@gmail.com>
Date: Sat, 22 Feb 2025 19:08:59 +0330
Subject: [PATCH] Set default direction of WHBoxLayout to document direction.

This feature makes it much easier to create RTL applications
and more importantly, bilingual (bidirectional) applications.
---
 src/Wt/WBoxLayout.C  | 18 +++++++++---------
 src/Wt/WBoxLayout.h  |  5 +++--
 src/Wt/WHBoxLayout.C | 21 ++++++++++++++++++++-
 src/Wt/WHBoxLayout.h |  5 +++++
 4 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/src/Wt/WBoxLayout.C b/src/Wt/WBoxLayout.C
index fc555a5c9f..c3eb60af74 100644
--- a/src/Wt/WBoxLayout.C
+++ b/src/Wt/WBoxLayout.C
@@ -53,7 +53,7 @@ std::unique_ptr<WLayoutItem> WBoxLayout::removeItem(WLayoutItem *item)
   int index = indexOf(item);
 
   if (index != -1) {
-    switch (direction_) {
+    switch (direction()) {
     case LayoutDirection::RightToLeft:
       if ((impl() && implementation() != LayoutImplementation::Flex) || !implementationIsFlexLayout())
         index = grid_.columns_.size() - 1 - index;
@@ -107,10 +107,10 @@ int WBoxLayout::count() const
   return grid_.rows_.size() * grid_.columns_.size();
 }
 
-void WBoxLayout::setDirection(LayoutDirection direction)
+void WBoxLayout::setDirection(LayoutDirection dir)
 {
-  if (direction_ != direction) {
-    direction_ = direction;
+  if (direction() != dir) {
+    direction_ = dir;
   }
 }
 
@@ -207,7 +207,7 @@ bool WBoxLayout::setStretchFactor(WLayout *layout, int stretch)
 
 void WBoxLayout::setStretchFactor(int i, int stretch)
 {
-  switch (direction_) {
+  switch (direction()) {
   case LayoutDirection::RightToLeft:
     if ((impl() && implementation() != LayoutImplementation::Flex) || !implementationIsFlexLayout())
       i = grid_.columns_.size() - 1 - i;
@@ -229,7 +229,7 @@ void WBoxLayout::insertItem(int index, std::unique_ptr<WLayoutItem> item,
 {
   WLayoutItem *it = item.get();
 
-  switch (direction_) {
+  switch (direction()) {
   case LayoutDirection::RightToLeft:
     if ((impl() && implementation() != LayoutImplementation::Flex) || !implementationIsFlexLayout())
       index = grid_.columns_.size() - index;
@@ -270,8 +270,8 @@ std::unique_ptr<WWidget> WBoxLayout::createSpacer(const WLength& size)
   std::unique_ptr<Spacer> spacer(new Spacer());
 
   if (size.toPixels() > 0) {
-    if (direction_ == LayoutDirection::LeftToRight ||
-        direction_ == LayoutDirection::RightToLeft)
+    if (direction() == LayoutDirection::LeftToRight ||
+        direction() == LayoutDirection::RightToLeft)
       spacer->setMinimumSize(size, WLength::Auto);
     else
       spacer->setMinimumSize(WLength::Auto, size);
@@ -289,7 +289,7 @@ void WBoxLayout::setResizable(int index, bool enabled,
     setPreferredImplementation(LayoutImplementation::JavaScript);
   }
 
-  switch (direction_) {
+  switch (direction()) {
   case LayoutDirection::RightToLeft:
     if ((impl() && implementation() != LayoutImplementation::Flex) || !implementationIsFlexLayout())
       index = grid_.columns_.size() - 1 - index;
diff --git a/src/Wt/WBoxLayout.h b/src/Wt/WBoxLayout.h
index 3c231d35f9..6a2347e632 100644
--- a/src/Wt/WBoxLayout.h
+++ b/src/Wt/WBoxLayout.h
@@ -121,13 +121,13 @@ class WT_API WBoxLayout : public WLayout
    *
    * \sa direction()
    */
-  void setDirection(LayoutDirection direction);
+  virtual void setDirection(LayoutDirection dir);
 
   /*! \brief Returns the layout direction.
    *
    * \sa setDirection()
    */
-  LayoutDirection direction() const { return direction_; }
+  virtual LayoutDirection direction()  { return direction_; }
 
   /*! \brief Sets spacing between each item.
    *
@@ -386,6 +386,7 @@ class WT_API WBoxLayout : public WLayout
   virtual bool implementationIsFlexLayout() const override;
 
 protected:
+  WBoxLayout(){}
   void insertItem(int index, std::unique_ptr<WLayoutItem> item, int stretch,
                   WFlags<AlignmentFlag> alignment);
 
diff --git a/src/Wt/WHBoxLayout.C b/src/Wt/WHBoxLayout.C
index 13aa2442a7..235b9ac2cc 100644
--- a/src/Wt/WHBoxLayout.C
+++ b/src/Wt/WHBoxLayout.C
@@ -5,11 +5,30 @@
  */
 
 #include "Wt/WHBoxLayout.h"
+#include "Wt/WApplication.h"
 
 namespace Wt {
 
 WHBoxLayout::WHBoxLayout()
-  : WBoxLayout(LayoutDirection::LeftToRight)
+  : syncDirection_(false)
 { }
 
+void WHBoxLayout::setDirection (LayoutDirection dir)
+{
+  syncDirection_ = true;
+  WBoxLayout::setDirection (dir);
+}
+
+LayoutDirection WHBoxLayout::direction (void)
+{
+
+  if (false == syncDirection_)
+  {
+
+    syncDirection_ = true;
+    WBoxLayout::setDirection (WApplication::instance()->layoutDirection());
+  }
+
+  return (WBoxLayout::direction());
+}
 }
diff --git a/src/Wt/WHBoxLayout.h b/src/Wt/WHBoxLayout.h
index d1c868464d..92758ce0e0 100644
--- a/src/Wt/WHBoxLayout.h
+++ b/src/Wt/WHBoxLayout.h
@@ -57,6 +57,11 @@ class WT_API WHBoxLayout : public WBoxLayout
   /*! \brief Creates a new horizontal box layout.
    */
   WHBoxLayout();
+  void setDirection (LayoutDirection dir) override;
+  LayoutDirection direction(void) override;
+
+private:
+  bool syncDirection_;
 };
 
 }