Merge branch '10.18' into 'master'10.18

add upstream 10.18

See merge request opensource-tracking/FreeFileSync!15

12 files changed, 150 insertions, 117 deletions

diff --git a/wx+/async_task.h b/wx+/async_task.h
index 04eac61c..1599c4d7 100644
--- a/wx+/async_task.h
+++ b/wx+/async_task.h
@@ -85,7 +85,7 @@ public:
 
             std::vector<std::unique_ptr<Task>> readyTasks; //Reentrancy; access to AsyncTasks::add is not protected! => evaluate outside eraseIf
 
-            eraseIf(tasks_, [&](std::unique_ptr<Task>& task)
+            std::erase_if(tasks_, [&](std::unique_ptr<Task>& task)
             {
                 if (task->resultReady())
                 {
diff --git a/wx+/context_menu.h b/wx+/context_menu.h
index d856db03..08a313bf 100644
--- a/wx+/context_menu.h
+++ b/wx+/context_menu.h
@@ -14,7 +14,7 @@
 #include <wx/app.h>
 
 /*
-A context menu supporting C++11 lambda callbacks!
+A context menu supporting lambda callbacks!
 
 Usage:
     ContextMenu menu;
@@ -56,7 +56,7 @@ public:
 
     void addSeparator() { menu_->AppendSeparator(); }
 
-    void addSubmenu(const wxString& label, ContextMenu& submenu, const wxBitmap* bmp = nullptr) //invalidates submenu!
+    void addSubmenu(const wxString& label, ContextMenu& submenu, const wxBitmap* bmp = nullptr, bool enabled = true) //invalidates submenu!
     {
         //transfer submenu commands:
         commandList_.insert(submenu.commandList_.begin(), submenu.commandList_.end());
@@ -67,6 +67,7 @@ public:
         wxMenuItem* newItem = new wxMenuItem(menu_.get(), wxID_ANY, label, L"", wxITEM_NORMAL, submenu.menu_.release()); //menu owns item, item owns submenu!
         if (bmp) newItem->SetBitmap(*bmp); //do not set AFTER appending item! wxWidgets screws up for yet another crappy reason
         menu_->Append(newItem);
+        if (!enabled) newItem->Enable(false);
     }
 
     void popup(wxWindow& wnd, const wxPoint& pos = wxDefaultPosition) //show popup menu + process lambdas
diff --git a/wx+/dc.h b/wx+/dc.h
index 894fb473..757942ca 100644
--- a/wx+/dc.h
+++ b/wx+/dc.h
@@ -56,7 +56,7 @@ int fastFromDIP(int d) //like wxWindow::FromDIP (but tied to primary monitor and
 #else //https://github.com/wxWidgets/wxWidgets/blob/master/src/common/wincmn.cpp#L2865
     static_assert(GTK_MAJOR_VERSION == 2);
     //GTK2 doesn't properly support high DPI: https://freefilesync.org/forum/viewtopic.php?t=6114
-	//=> requires general fix at wxWidgets-level
+    //=> requires general fix at wxWidgets-level
     assert(wxTheApp); //only call after wxWidgets was initalized!
     static const int dpiY = wxScreenDC().GetPPI().y; //perf: buffering for calls to ::GetDeviceCaps() needed!?
     const int defaultDpi = 96;
diff --git a/wx+/font_size.h b/wx+/font_size.h
index 2f2d377c..d25dfede 100644
--- a/wx+/font_size.h
+++ b/wx+/font_size.h
@@ -35,7 +35,7 @@ void setRelativeFontSize(wxWindow& control, double factor)
     wxFont font = control.GetFont();
     font.SetPointSize(numeric::round(wxNORMAL_FONT->GetPointSize() * factor));
     control.SetFont(font);
-};
+}
 
 
 inline
@@ -46,7 +46,7 @@ void setMainInstructionFont(wxWindow& control)
     font.SetWeight(wxFONTWEIGHT_BOLD);
 
     control.SetFont(font);
-};
+}
 }
 
 #endif //FONT_SIZE_H_23849632846734343234532
diff --git a/wx+/graph.cpp b/wx+/graph.cpp
index aac2cc10..a6d0f19d 100644
--- a/wx+/graph.cpp
+++ b/wx+/graph.cpp
@@ -151,7 +151,7 @@ void drawXLabel(wxDC& dc, double xMin, double xMax, int blockCount, const Conver
         return;
 
     wxDCPenChanger dummy(dc, wxColor(192, 192, 192)); //light grey => not accessible! but no big deal...
-    wxDCTextColourChanger dummy2(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
+    wxDCTextColourChanger textColor(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
 
     const double valRangePerBlock = (xMax - xMin) / blockCount;
 
@@ -179,7 +179,7 @@ void drawYLabel(wxDC& dc, double yMin, double yMax, int blockCount, const Conver
         return;
 
     wxDCPenChanger dummy(dc, wxColor(192, 192, 192)); //light grey => not accessible! but no big deal...
-    wxDCTextColourChanger dummy2(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
+    wxDCTextColourChanger textColor(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
 
     const double valRangePerBlock = (yMax - yMin) / blockCount;
 
@@ -225,13 +225,12 @@ void drawCornerText(wxDC& dc, const wxRect& graphArea, const wxString& txt, Grap
             drawPos.y += graphArea.height - boxExtent.GetHeight();
             break;
     }
-    {
+
         //add text shadow to improve readability:
-        wxDCTextColourChanger dummy(dc, colorBack);
-        dc.DrawText(txt, drawPos + border + wxSize(fastFromDIP(1), fastFromDIP(1)));
-    }
+	wxDCTextColourChanger textColor(dc, colorBack);
+     dc.DrawText(txt, drawPos + border + wxSize(fastFromDIP(1), fastFromDIP(1)));
 
-    wxDCTextColourChanger dummy(dc, colorText);
+	textColor.Set(colorText);
     dc.DrawText(txt, drawPos + border);
 }
 
diff --git a/wx+/grid.cpp b/wx+/grid.cpp
index 851146bc..0613e14f 100644
--- a/wx+/grid.cpp
+++ b/wx+/grid.cpp
@@ -249,7 +249,7 @@ wxRect GridData::drawColumnLabelBackground(wxDC& dc, const wxRect& rect, bool hi
 
 void GridData::drawColumnLabelText(wxDC& dc, const wxRect& rect, const std::wstring& text)
 {
-    wxDCTextColourChanger dummy(dc, getColorLabelText()); //accessibility: always set both foreground AND background colors!
+    wxDCTextColourChanger textColor(dc, getColorLabelText()); //accessibility: always set both foreground AND background colors!
     drawCellText(dc, rect, text, wxALIGN_LEFT | wxALIGN_CENTER_VERTICAL);
 }
 
@@ -452,9 +452,7 @@ public:
     {
         wxClientDC dc(this);
 
-        wxFont labelFont = GetFont();
-        //labelFont.SetWeight(wxFONTWEIGHT_BOLD);
-        dc.SetFont(labelFont); //harmonize with RowLabelWin::render()!
+        dc.SetFont(GetFont()); //harmonize with RowLabelWin::render()!
 
         int bestWidth = 0;
         for (ptrdiff_t i = rowFrom; i <= rowTo; ++i)
@@ -504,9 +502,7 @@ private:
     {
         clearArea(dc, rect, wxSystemSettings::GetColour(/*!renderAsEnabled(*this) ? wxSYS_COLOUR_BTNFACE :*/wxSYS_COLOUR_WINDOW));
 
-        wxFont labelFont = GetFont();
-        //labelFont.SetWeight(wxFONTWEIGHT_BOLD);
-        dc.SetFont(labelFont); //harmonize with RowLabelWin::getBestWidth()!
+        dc.SetFont(GetFont()); //harmonize with RowLabelWin::getBestWidth()!
 
         auto rowRange = getRowsOnClient(rect); //returns range [begin, end)
         for (auto row = rowRange.first; row < rowRange.second; ++row)
@@ -524,7 +520,7 @@ private:
     {
         //clearArea(dc, rect, getColorRowLabel());
         dc.GradientFillLinear(rect, getColorLabelGradientFrom(), getColorLabelGradientTo(), wxEAST); //clear overlapping cells
-        wxDCTextColourChanger dummy3(dc, getColorLabelText()); //accessibility: always set both foreground AND background colors!
+        wxDCTextColourChanger textColor(dc, getColorLabelText()); //accessibility: always set both foreground AND background colors!
 
         //label text
         wxRect textRect = rect;
@@ -623,10 +619,10 @@ private:
 
         //coordinate with "colLabelHeight" in Grid constructor:
         wxFont labelFont = GetFont();
-        labelFont.SetWeight(wxFONTWEIGHT_BOLD);
+        labelFont.MakeBold();
         dc.SetFont(labelFont);
 
-        wxDCTextColourChanger dummy(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT)); //use user setting for labels
+        wxDCTextColourChanger textColor(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT)); //use user setting for labels
 
         const int colLabelHeight = refParent().colLabelHeight_;
 
@@ -893,7 +889,7 @@ private:
 
         dc.SetFont(GetFont()); //harmonize with Grid::getBestColumnSize()
 
-        wxDCTextColourChanger dummy(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT)); //use user setting for labels
+        wxDCTextColourChanger textColor(dc, wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT)); //use user setting for labels
 
         std::vector<ColumnWidth> absWidths = refParent().getColWidths(); //resolve stretched widths
         {
@@ -1313,7 +1309,7 @@ Grid::Grid(wxWindow* parent,
     {
         //coordinate with ColLabelWin::render():
         wxFont labelFont = colLabelWin_->GetFont();
-        labelFont.SetWeight(wxFONTWEIGHT_BOLD);
+        labelFont.MakeBold();
         return labelFont.GetPixelSize().GetHeight();
     }();
 
@@ -1491,22 +1487,51 @@ wxSize Grid::GetSizeAvailableForScrollTarget(const wxSize& size)
     }();
 
     //2. try(!) to determine scrollbar sizes:
+#if GTK_MAJOR_VERSION == 2
+	/* Ubuntu 19.10: "scrollbar-spacing" has a default value of 3: https://developer.gnome.org/gtk2/stable/GtkScrolledWindow.html#GtkScrolledWindow--s-scrollbar-spacing
+		=> the default Ubuntu theme (but also our Gtk2Styles.rc) set it to 0, but still the first call to gtk_widget_style_get() returns 3: why?
+		=> maybe styles are applied asynchronously? GetClientSize() is affected by this, so can't use!
+		=> always ignore spacing to get consistent scrollbar dimensions!  */
+    GtkScrolledWindow* scrollWin = GTK_SCROLLED_WINDOW(wxWindow::m_widget);
+    assert(scrollWin);
+    GtkWidget* rangeH = ::gtk_scrolled_window_get_hscrollbar(scrollWin);
+    GtkWidget* rangeV = ::gtk_scrolled_window_get_vscrollbar(scrollWin);
+
+    GtkRequisition reqH = {};
+    GtkRequisition reqV = {};
+    if (rangeH) ::gtk_widget_size_request(rangeH, &reqH);
+    if (rangeV) ::gtk_widget_size_request(rangeV, &reqV);
+    assert(reqH.width > 0 && reqH.height > 0);
+    assert(reqV.width > 0 && reqV.height > 0);
+
+    const wxSize scrollBarSizeTmp(reqV.width, reqH.height);
+    assert(scrollBarHeightH_ == 0 || scrollBarHeightH_ == scrollBarSizeTmp.y);
+    assert(scrollBarWidthV_  == 0 || scrollBarWidthV_  == scrollBarSizeTmp.x);
+
+#elif GTK_MAJOR_VERSION == 3
+		//scrollbar size increases dynamically on mouse-hover! 
+		//see "overlay scrolling": https://developer.gnome.org/gtk3/stable/GtkScrolledWindow.html#gtk-scrolled-window-set-overlay-scrolling
+		//luckily "scrollbar-spacing" is stable on GTK3
     const wxSize scrollBarSizeTmp = GetSize() - GetClientSize();
-    assert(scrollBarHeightH_ == 0 || scrollBarSizeTmp.y == 0 || scrollBarHeightH_ == scrollBarSizeTmp.y);
-    assert(scrollBarWidthV_  == 0 || scrollBarSizeTmp.x == 0 || scrollBarWidthV_  == scrollBarSizeTmp.x);
+
+    assert(scrollBarSizeTmp.x == 0 || scrollBarSizeTmp.x == 6 || scrollBarSizeTmp.x == 13); //lame hard-coded numbers (from Ubuntu 19.10)
+    assert(scrollBarSizeTmp.y == 0 || scrollBarSizeTmp.y == 6 || scrollBarSizeTmp.y == 13); //=> but let's have a *close* eye on scrollbar fluctuation!
+#else
+#error unknown GTK version!
+#endif
     scrollBarHeightH_ = std::max(scrollBarHeightH_, scrollBarSizeTmp.y);
     scrollBarWidthV_  = std::max(scrollBarWidthV_,  scrollBarSizeTmp.x);
     //this function is called again by wxScrollHelper::AdjustScrollbars() if SB_SHOW_ALWAYS-scrollbars are not yet shown => scrollbar size > 0 eventually!
-
+	   
     //-----------------------------------------------------------------------------
     //harmonize with Grid::updateWindowSizes()!
     wxSize sizeAvail = size - wxSize(rowLabelWidth, colLabelHeight_);
 
     //EXCEPTION: space consumed by SB_SHOW_ALWAYS-scrollbars is *never* available for "scroll target"; see wxScrollHelper::AdjustScrollbars()
     if (showScrollbarH_ == SB_SHOW_ALWAYS)
-        sizeAvail.y -= scrollBarHeightH_;
+        sizeAvail.y -= (scrollBarHeightH_ > 0 ? scrollBarHeightH_ : /*fallback:*/ scrollBarWidthV_);
     if (showScrollbarV_ == SB_SHOW_ALWAYS)
-        sizeAvail.x -= scrollBarWidthV_;
+        sizeAvail.x -= (scrollBarWidthV_ > 0 ? scrollBarWidthV_ : /*fallback:*/ scrollBarHeightH_);
 
     return wxSize(std::max(0, sizeAvail.x),
                   std::max(0, sizeAvail.y));
@@ -1879,10 +1904,10 @@ void Grid::showScrollBars(Grid::ScrollBarStatus horizontal, Grid::ScrollBarStatu
         assert(false);
         return GTK_POLICY_AUTOMATIC;
     };
-
-    GtkWidget* gridWidget = wxWindow::m_widget;
-    GtkScrolledWindow* scrolledWindow = GTK_SCROLLED_WINDOW(gridWidget);
-    ::gtk_scrolled_window_set_policy(scrolledWindow,
+	 
+    GtkScrolledWindow* scrollWin = GTK_SCROLLED_WINDOW(wxWindow::m_widget);
+    assert(scrollWin);
+    ::gtk_scrolled_window_set_policy(scrollWin,
                                      mapStatus(horizontal),
                                      mapStatus(vertical));
 
diff --git a/wx+/grid.h b/wx+/grid.h
index cecdfafe..74dc25b2 100644
--- a/wx+/grid.h
+++ b/wx+/grid.h
@@ -333,15 +333,13 @@ private:
 
     ColumnType colToType(size_t col) const; //returns ColumnType::NONE on error
 
-    /*
-    Visual layout:
-        --------------------------------
-        |CornerWin   | ColLabelWin     |
-        |------------------------------|
-        |RowLabelWin | MainWin         |
-        |            |                 |
-        --------------------------------
-    */
+    /*  Grid window layout:
+            _______________________________
+            | CornerWin   | ColLabelWin   |
+            |_____________|_______________|
+            | RowLabelWin | MainWin       |
+            |             |               |
+            |_____________|_______________| */
     CornerWin*   cornerWin_;
     RowLabelWin* rowLabelWin_;
     ColLabelWin* colLabelWin_;
diff --git a/wx+/image_resources.cpp b/wx+/image_resources.cpp
index faabbb2a..91189ba6 100644
--- a/wx+/image_resources.cpp
+++ b/wx+/image_resources.cpp
@@ -11,10 +11,10 @@
 #include <zen/globals.h>
 #include <zen/perf.h>
 #include <zen/thread.h>
-#include <wx/wfstream.h>
+#include <zen/file_io.h>
 #include <wx/zipstrm.h>
-#include <wx/image.h>
 #include <wx/mstream.h>
+#include <wx/image.h>
 #include <xBRZ/src/xbrz.h>
 #include <xBRZ/src/xbrz_tools.h>
 #include "image_tools.h"
@@ -143,24 +143,6 @@ private:
     //hardware_concurrency() == 0 if "not computable or well defined"
 };
 
-
-void loadAnimFromZip(wxZipInputStream& zipInput, wxAnimation& anim)
-{
-    //work around wxWidgets bug:
-    //construct seekable input stream (zip-input stream is not seekable) for wxAnimation::Load()
-    //luckily this method call is very fast: below measurement precision!
-    std::vector<std::byte> data;
-    data.reserve(10000);
-
-    int newValue = 0;
-    while ((newValue = zipInput.GetC()) != wxEOF)
-        data.push_back(static_cast<std::byte>(newValue));
-
-    wxMemoryInputStream seekAbleStream(&data.front(), data.size()); //stream does not take ownership of data
-
-    anim.Load(seekAbleStream, wxANIMATION_TYPE_GIF);
-}
-
 //================================================================================================
 //================================================================================================
 
@@ -204,44 +186,59 @@ void GlobalBitmaps::init(const Zstring& filePath)
 {
     assert(bitmaps_.empty() && anims_.empty());
 
-    wxFFileInputStream input(utfTo<wxString>(filePath));
-    if (input.IsOk()) //if not... we don't want to react too harsh here
+    //wxFFileInputStream/wxZipInputStream loads in junks of 512 bytes => WTF!!! => implement sane file loading:
+    try
     {
-        //activate support for .png files
-        wxImage::AddHandler(new wxPNGHandler); //ownership passed
-
-        wxZipInputStream streamIn(input, wxConvUTF8);
-        //do NOT rely on wxConvLocal! On failure shows unhelpful popup "Cannot convert from the charset 'Unknown encoding (-1)'!"
-
-        //do we need xBRZ scaling for high quality DPI images?
-        const int hqScale = std::clamp<int>(std::ceil(fastFromDIP(1000) / 1000.0), 1, xbrz::SCALE_FACTOR_MAX);
-        //even for 125% DPI scaling, "2xBRZ + bilinear downscale" gives a better result than mere "125% bilinear upscale"!
-        if (hqScale > 1)
-            dpiScaler_ = std::make_unique<DpiParallelScaler>(hqScale);
-
-        while (const auto& entry = std::unique_ptr<wxZipEntry>(streamIn.GetNextEntry())) //take ownership!)
-        {
-            const wxString name = entry->GetName();
-
-            if (endsWith(name, L".png"))
-            {
-                wxImage img(streamIn, wxBITMAP_TYPE_PNG);
-
-                //end this alpha/no-alpha/mask/wxDC::DrawBitmap/RTL/high-contrast-scheme interoperability nightmare here and now!!!!
-                //=> there's only one type of wxImage: with alpha channel, no mask!!!
-                convertToVanillaImage(img);
-
-                if (dpiScaler_)
-                    dpiScaler_->add(name, img); //scale in parallel!
-                else
-                    bitmaps_.emplace(name, img);
-            }
-            else if (endsWith(name, L".gif"))
-                loadAnimFromZip(streamIn, anims_[name]);
-            else
-                assert(false);
-        }
+        const std::string rawStream = loadBinContainer<std::string>(filePath, nullptr /*notifyUnbufferedIO*/); //throw FileError
+		wxMemoryInputStream memStream(rawStream.c_str(), rawStream.size()); //does not take ownership
+		wxZipInputStream zipStream(memStream, wxConvUTF8);
+		//do NOT rely on wxConvLocal! On failure shows unhelpful popup "Cannot convert from the charset 'Unknown encoding (-1)'!"
+
+		//activate support for .png files
+		wxImage::AddHandler(new wxPNGHandler); //ownership passed
+
+		//do we need xBRZ scaling for high quality DPI images?
+		const int hqScale = std::clamp<int>(std::ceil(fastFromDIP(1000) / 1000.0), 1, xbrz::SCALE_FACTOR_MAX);
+		//even for 125% DPI scaling, "2xBRZ + bilinear downscale" gives a better result than mere "125% bilinear upscale"!
+		if (hqScale > 1)
+			dpiScaler_ = std::make_unique<DpiParallelScaler>(hqScale);
+
+		while (const auto& entry = std::unique_ptr<wxZipEntry>(zipStream.GetNextEntry())) //take ownership!)
+		{
+			const wxString name = entry->GetName();
+
+			if (endsWith(name, L".png"))
+			{
+				wxImage img(zipStream, wxBITMAP_TYPE_PNG);
+				assert(img.IsOk());
+
+				//end this alpha/no-alpha/mask/wxDC::DrawBitmap/RTL/high-contrast-scheme interoperability nightmare here and now!!!!
+				//=> there's only one type of wxImage: with alpha channel, no mask!!!
+				convertToVanillaImage(img);
+
+				if (dpiScaler_)
+					dpiScaler_->add(name, img); //scale in parallel!
+				else
+					bitmaps_.emplace(name, img);
+			}
+			else if (endsWith(name, L".gif"))
+			{
+				//work around wxWidgets bug: wxAnimation::Load() requires seekable input stream (zip-input stream is not seekable)
+				std::string stream(entry->GetSize(), '\0');
+				if (!stream.empty() && zipStream.ReadAll(&stream[0], stream.size()))
+				{
+					wxMemoryInputStream seekAbleStream(stream.c_str(), stream.size()); //stream does not take ownership of data
+					[[maybe_unused]] const bool loadSuccess = anims_[name].Load(seekAbleStream, wxANIMATION_TYPE_GIF);
+					assert(loadSuccess);
+				}
+				else
+					assert(false);
+			}
+			else
+				assert(false);
+		}
     }
+    catch (FileError&) { assert(false); }
 }
 
 
diff --git a/wx+/image_tools.cpp b/wx+/image_tools.cpp
index b314e801..0f248057 100644
--- a/wx+/image_tools.cpp
+++ b/wx+/image_tools.cpp
@@ -203,15 +203,15 @@ wxImage zen::createImageFromText(const wxString& text, const wxFont& font, const
 }
 
 
-wxBitmap zen::layOver(const wxBitmap& back, const wxBitmap& front,  int alignment)
+wxImage zen::layOver(const wxImage& back, const wxImage& front, int alignment)
 {
     if (!front.IsOk()) return back;
+    assert(front.HasAlpha() && back.HasAlpha());
 
     const int width  = std::max(back.GetWidth(),  front.GetWidth());
     const int height = std::max(back.GetHeight(), front.GetHeight());
 
-    assert(front.HasAlpha() == back.HasAlpha()); //we don't support mixed-mode brittleness!
-    const int offsetX = [&]
+	const int offsetX = [&]
     {
         if (alignment & wxALIGN_RIGHT)
             return back.GetWidth() - front.GetWidth();
@@ -239,8 +239,8 @@ wxBitmap zen::layOver(const wxBitmap& back, const wxBitmap& front,  int alignmen
     ::memset(output.GetAlpha(), wxIMAGE_ALPHA_TRANSPARENT, width * height);
 
     const wxPoint posBack(std::max(-offsetX, 0), std::max(-offsetY, 0));
-    writeToImage(output, back .ConvertToImage(), posBack);
-    writeToImage(output, front.ConvertToImage(), posBack + wxPoint(offsetX, offsetY));
+    writeToImage(output, back , posBack);
+    writeToImage(output, front, posBack + wxPoint(offsetX, offsetY));
     return output;
 }
 
diff --git a/wx+/image_tools.h b/wx+/image_tools.h
index 2a0dd0d4..d72597ef 100644
--- a/wx+/image_tools.h
+++ b/wx+/image_tools.h
@@ -34,7 +34,7 @@ wxImage stackImages(const wxImage& img1, const wxImage& img2, ImageStackLayout d
 
 wxImage createImageFromText(const wxString& text, const wxFont& font, const wxColor& col, ImageStackAlignment textAlign = ImageStackAlignment::LEFT); //CENTER/LEFT/RIGHT
 
-wxBitmap layOver(const wxBitmap& back, const wxBitmap& front, int alignment = wxALIGN_CENTER);
+wxImage layOver(const wxImage& back, const wxImage& front, int alignment = wxALIGN_CENTER);
 
 wxImage greyScale(const wxImage& img); //greyscale + brightness adaption
 wxBitmap greyScale(const wxBitmap& bmp); //
@@ -213,7 +213,7 @@ wxColor gradient(const wxColor& from, const wxColor& to, double fraction)
 inline
 wxColor hsvColor(double h, double s, double v) //h within [0, 360), s, v within [0, 1]
 {
-    //https://de.wikipedia.org/wiki/HSV-Farbraum
+    //https://en.wikipedia.org/wiki/HSL_and_HSV
 
     //make input values fit into bounds
     if (h > 360)
diff --git a/wx+/rtl.h b/wx+/rtl.h
index 0cae9bac..0adb6037 100644
--- a/wx+/rtl.h
+++ b/wx+/rtl.h
@@ -20,6 +20,7 @@ void drawBitmapRtlNoMirror(wxDC& dc, const wxBitmap& bmp, const wxRect& rect, in
 //wxDC::DrawIcon DOES mirror by default -> implement RTL support when needed
 
 wxBitmap mirrorIfRtl(const wxBitmap& bmp);
+wxImage  mirrorIfRtl(const wxImage& bmp);
 
 //manual text flow correction: https://www.w3.org/International/articles/inline-bidi-markup/
 
@@ -93,6 +94,15 @@ void drawBitmapRtlNoMirror(wxDC& dc, const wxBitmap& bmp, const wxRect& rect, in
 }
 
 
+inline 
+wxImage mirrorIfRtl(const wxImage& bmp)
+{
+    if (wxTheApp->GetLayoutDirection() == wxLayout_RightToLeft)
+        return bmp.Mirror();
+    else
+        return bmp;}
+
+
 inline
 wxBitmap mirrorIfRtl(const wxBitmap& bmp)
 {
diff --git a/wx+/toggle_button.h b/wx+/toggle_button.h
index f61c3857..98ca32b3 100644
--- a/wx+/toggle_button.h
+++ b/wx+/toggle_button.h
@@ -28,8 +28,8 @@ public:
         SetLayoutDirection(wxLayout_LeftToRight); //avoid mirroring RTL languages like Hebrew or Arabic
     }
 
-    void init(const wxBitmap& activeBmp,
-              const wxBitmap& inactiveBmp);
+    void init(const wxBitmap& bmpActive,
+              const wxBitmap& bmpInactive);
 
     void setActive(bool value);
     bool isActive() const { return active_; }
@@ -37,8 +37,8 @@ public:
 
 private:
     bool active_ = false;
-    wxBitmap activeBmp_;
-    wxBitmap inactiveBmp_;
+    wxBitmap bmpActive_;
+    wxBitmap bmpInactive_;
 };
 
 
@@ -49,21 +49,24 @@ private:
 
 //######################## implementation ########################
 inline
-void ToggleButton::init(const wxBitmap& activeBmp,
-                        const wxBitmap& inactiveBmp)
+void ToggleButton::init(const wxBitmap& bmpActive,
+                        const wxBitmap& bmpInactive)
 {
-    activeBmp_   = activeBmp;
-    inactiveBmp_ = inactiveBmp;
+    bmpActive_   = bmpActive;
+    bmpInactive_ = bmpInactive;
 
-    setActive(active_);
+    setImage(*this, active_ ? bmpActive_ : bmpInactive_);
 }
 
 
 inline
 void ToggleButton::setActive(bool value)
 {
-    active_ = value;
-    setImage(*this, active_ ? activeBmp_ : inactiveBmp_);
+    if (active_ != value)
+    {
+        active_ = value;
+        setImage(*this, active_ ? bmpActive_ : bmpInactive_);
+    }
 }
 }