Add ShowBrushPreview command so the user can hide the brush preview with a keyboard shortcut (fix #792)

data/gui.xml

@@ -726,6 +726,8 @@
           <item command="ShowSelectionEdges" text="&amp;Selection Edges" />
           <item command="ShowGrid" text="&amp;Grid" />
           <item command="ShowPixelGrid" text="&amp;Pixel Grid" />
+          <separator />
+          <item command="ShowBrushPreview" text="&amp;Brush Preview" />
         </menu>
         <separator />
         <menu text="&amp;Grid">

data/pref.xml

@@ -289,6 +289,7 @@
       <option id="selection_edges" type="bool" default="true" />
       <option id="grid" type="bool" default="false" migrate="grid.visible" />
       <option id="pixel_grid" type="bool" default="false" migrate="pixel_grid.visible" />
+      <option id="brush_preview" type="bool" default="true" />
     </section>
   </document>
 

src/app/commands/cmd_show.cpp

@@ -11,6 +11,7 @@
 
 #include "app/commands/command.h"
 #include "app/context.h"
+#include "app/modules/gui.h"
 #include "app/pref/preferences.h"
 
 namespace app {
@@ -118,6 +119,33 @@ protected:
   }
 };
 
+class ShowBrushPreviewCommand : public Command {
+public:
+  ShowBrushPreviewCommand()
+    : Command("ShowBrushPreview",
+              "Show Brush Preview",
+              CmdUIOnlyFlag) {
+  }
+
+  Command* clone() const override { return new ShowBrushPreviewCommand(*this); }
+
+protected:
+  bool onChecked(Context* ctx) override {
+    DocumentPreferences& docPref = Preferences::instance().document(ctx->activeDocument());
+    return docPref.show.brushPreview();
+  }
+
+  void onExecute(Context* ctx) override {
+    DocumentPreferences& docPref = Preferences::instance().document(ctx->activeDocument());
+    docPref.show.brushPreview(!docPref.show.brushPreview());
+
+    // TODO we shouldn't need this, but it happens to be that the
+    // Preview editor isn't being updated correctly when we change the
+    // brush preview state.
+    update_screen_for_document(ctx->activeDocument());
+  }
+};
+
 Command* CommandFactory::createShowExtrasCommand()
 {
   return new ShowExtrasCommand;
@@ -138,4 +166,9 @@ Command* CommandFactory::createShowSelectionEdgesCommand()
   return new ShowSelectionEdgesCommand;
 }
 
+Command* CommandFactory::createShowBrushPreviewCommand()
+{
+  return new ShowBrushPreviewCommand;
+}
+
 } // namespace app

src/app/commands/commands_list.h

@@ -116,6 +116,7 @@ FOR_EACH_COMMAND(SetLoopSection)
 FOR_EACH_COMMAND(SetPalette)
 FOR_EACH_COMMAND(SetPaletteEntrySize)
 FOR_EACH_COMMAND(SetSameInk)
+FOR_EACH_COMMAND(ShowBrushPreview)
 FOR_EACH_COMMAND(ShowExtras)
 FOR_EACH_COMMAND(ShowGrid)
 FOR_EACH_COMMAND(ShowOnionSkin)

src/app/ui/editor/brush_preview.cpp

@@ -96,7 +96,8 @@ void BrushPreview::show(const gfx::Point& screenPos)
                                      m_editor->getUpdateRegion());
 
   // Get cursor color
-  app::Color app_cursor_color = Preferences::instance().editor.cursorColor();
+  const auto& pref = Preferences::instance();
+  app::Color app_cursor_color = pref.editor.cursorColor();
   gfx::Color ui_cursor_color = color_utils::color_for_ui(app_cursor_color);
   m_blackAndWhiteNegative = (app_cursor_color.getType() == app::Color::MaskType);
 
@@ -138,7 +139,21 @@ void BrushPreview::show(const gfx::Point& screenPos)
   }
 
   bool usePreview = false;
-  switch (Preferences::instance().editor.brushPreview()) {
+
+  auto brushPreview = pref.editor.brushPreview();
+
+  // If the brush preview is hidden, we step down one level. E.g. If
+  // we have full-brush preview, we move to edges, or if it's edges,
+  // we don't show it at all.
+  if (!m_editor->docPref().show.brushPreview()) {
+    switch (brushPreview) {
+      case app::gen::BrushPreview::NONE: break;
+      case app::gen::BrushPreview::EDGES: brushPreview = app::gen::BrushPreview::NONE; break;
+      case app::gen::BrushPreview::FULL: brushPreview = app::gen::BrushPreview::EDGES; break;
+    }
+  }
+
+  switch (brushPreview) {
     case app::gen::BrushPreview::NONE:
       m_type = CROSS;
       break;

src/app/ui/editor/editor.h

@@ -120,6 +120,7 @@ namespace app {
     Sprite* sprite() { return m_sprite; }
     Layer* layer() { return m_layer; }
     frame_t frame() { return m_frame; }
+    DocumentPreferences& docPref() { return m_docPref; }
 
     void getSite(Site* site) const;
     Site getSite() const;