Fix drawing straight lines w/Pencil tool and Shift+right button

https://community.aseprite.org/t/eraser-tool-right-click-shift-should-work/726

src/app/tools/tool_loop.h

@@ -14,6 +14,7 @@
 #include "doc/frame.h"
 #include "filters/tiled_mode.h"
 #include "gfx/point.h"
+#include "gfx/rect.h"
 
 namespace gfx {
   class Region;

src/app/ui/editor/drawing_state.cpp

@@ -74,9 +74,13 @@ void DrawingState::initToolLoop(Editor* editor,
      static_cast<LayerImage*>(m_toolLoop->getLayer())->blendMode():
      BlendMode::NEG_BW));
 
+  ASSERT(!m_toolLoopManager->isCanceled());
+
   m_toolLoopManager->prepareLoop(pointer);
   m_toolLoopManager->pressButton(pointer);
 
+  ASSERT(!m_toolLoopManager->isCanceled());
+
   editor->captureMouse();
 }
 
@@ -100,14 +104,40 @@ bool DrawingState::onMouseDown(Editor* editor, MouseMessage* msg)
   if (!editor->hasCapture())
     editor->captureMouse();
 
+  tools::Pointer pointer = pointer_from_msg(editor, msg);
+
+  // Check if this drawing state was started with a Shift+Pencil tool
+  // and now the user pressed the right button to draw the straight
+  // line with the background color.
+  bool recreateLoop = false;
+  if (m_type == DrawingType::LineFreehand &&
+      !m_mousePressedReceived) {
+    recreateLoop = true;
+  }
+
   m_mousePressedReceived = true;
 
   // Notify the mouse button down to the tool loop manager.
-  m_toolLoopManager->pressButton(pointer_from_msg(editor, msg));
+  m_toolLoopManager->pressButton(pointer);
+
+  // Store the isCanceled flag, because destroyLoopIfCanceled might
+  // destroy the tool loop manager.
+  ASSERT(m_toolLoopManager);
+  const bool isCanceled = m_toolLoopManager->isCanceled();
 
   // The user might have canceled by the tool loop clicking with the
   // secondary mouse button.
   destroyLoopIfCanceled(editor);
+
+  // In this case, the user canceled the straight line preview
+  // (Shift+Pencil) pressing the right-click (other mouse button). Now
+  // we have to restart the loop calling
+  // checkStartDrawingStraightLine() with the right-button.
+  if (recreateLoop && isCanceled) {
+    ASSERT(!m_toolLoopManager);
+    checkStartDrawingStraightLine(editor, msg);
+  }
+
   return true;
 }
 
@@ -142,7 +172,8 @@ bool DrawingState::onMouseUp(Editor* editor, MouseMessage* msg)
   // button, if the Shift key is pressed, the whole ToolLoop starts
   // again.
   if (Preferences::instance().editor.straightLinePreview())
-    checkStartDrawingStraightLine(editor);
+    checkStartDrawingStraightLine(editor, msg);
+
   return true;
 }
 
@@ -208,7 +239,7 @@ bool DrawingState::onKeyUp(Editor* editor, KeyMessage* msg)
       // released and the user didn't press the mouse button.
       (m_type == DrawingType::LineFreehand &&
        !m_mousePressedReceived &&
-       !editor->startStraightLineWithFreehandTool())) {
+       !editor->startStraightLineWithFreehandTool(nullptr))) {
     m_toolLoop->cancel();
   }
 

src/app/ui/editor/drawing_state.h

@@ -8,13 +8,13 @@
 #define APP_UI_EDITOR_DRAWING_STATE_H_INCLUDED
 #pragma once
 
+#include "app/tools/pointer.h"
 #include "app/ui/editor/standby_state.h"
 #include "obs/connection.h"
 #include <memory>
 
 namespace app {
   namespace tools {
-    class Pointer;
     class ToolLoop;
     class ToolLoopManager;
   }

src/app/ui/editor/editor.cpp

@@ -1556,15 +1556,17 @@ app::Color Editor::getColorByPosition(const gfx::Point& mousePos)
     return app::Color::fromMask();
 }
 
-bool Editor::startStraightLineWithFreehandTool()
+bool Editor::startStraightLineWithFreehandTool(const ui::MouseMessage* msg)
 {
   tools::Tool* tool = App::instance()->activeToolManager()->selectedTool();
+  // TODO add support for more buttons (X1, X2, etc.)
+  int i = (msg && msg->right() ? 1: 0);
   return
     (isActive() &&
      (hasMouse() || hasCapture()) &&
      tool &&
-     tool->getController(0)->isFreehand() &&
-     tool->getInk(0)->isPaint() &&
+     tool->getController(i)->isFreehand() &&
+     tool->getInk(i)->isPaint() &&
      (getCustomizationDelegate()
       ->getPressedKeyAction(KeyContext::FreehandTool) & KeyAction::StraightLineFromLastPoint) == KeyAction::StraightLineFromLastPoint &&
      document()->lastDrawingPoint() != app::Document::NoLastDrawingPoint());

src/app/ui/editor/editor.h

@@ -195,7 +195,6 @@ namespace app {
 
     tools::ToolLoopModifiers getToolLoopModifiers() const { return m_toolLoopModifiers; }
     bool isAutoSelectLayer() const;
-    bool isSecondaryButton() const { return m_secondaryButton; }
 
     // Returns true if we are able to draw in the current doc/sprite/layer/cel.
     bool canDraw();
@@ -268,7 +267,7 @@ namespace app {
 
     // Returns true if the Shift key to draw straight lines with a
     // freehand tool is pressed.
-    bool startStraightLineWithFreehandTool();
+    bool startStraightLineWithFreehandTool(const ui::MouseMessage* msg);
 
   protected:
     bool onProcessMessage(ui::Message* msg) override;

src/app/ui/editor/glue.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2016  David Capello
+// Copyright (C) 2016-2017  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -16,14 +16,15 @@ namespace app {
 
 // Code to convert "ui" messages to "tools" mouse pointers
 
-inline tools::Pointer::Button button_from_msg(ui::MouseMessage* msg) {
+inline tools::Pointer::Button button_from_msg(const ui::MouseMessage* msg) {
   return
     (msg->right() ? tools::Pointer::Right:
      (msg->middle() ? tools::Pointer::Middle:
                       tools::Pointer::Left));
 }
 
-inline tools::Pointer pointer_from_msg(Editor* editor, ui::MouseMessage* msg) {
+inline tools::Pointer pointer_from_msg(Editor* editor,
+                                       const ui::MouseMessage* msg) {
   return
     tools::Pointer(editor->screenToEditor(msg->position()),
                    button_from_msg(msg));

src/app/ui/editor/standby_state.cpp

@@ -319,7 +319,7 @@ bool StandbyState::onMouseDown(Editor* editor, MouseMessage* msg)
     // Shift+click on Pencil tool starts a line onMouseDown() when the
     // preview (onKeyDown) is disabled.
     if (!Preferences::instance().editor.straightLinePreview() &&
-        checkStartDrawingStraightLine(editor)) {
+        checkStartDrawingStraightLine(editor, msg)) {
       // Send first mouse down to draw the straight line and start the
       // freehand mode.
       editor->getState()->onMouseDown(editor, msg);
@@ -501,7 +501,7 @@ bool StandbyState::onSetCursor(Editor* editor, const gfx::Point& mouseScreenPos)
 bool StandbyState::onKeyDown(Editor* editor, KeyMessage* msg)
 {
   if (Preferences::instance().editor.straightLinePreview() &&
-      checkStartDrawingStraightLine(editor))
+      checkStartDrawingStraightLine(editor, nullptr))
     return true;
   return false;
 }
@@ -607,6 +607,7 @@ DrawingState* StandbyState::startDrawingState(Editor* editor,
   tools::ToolLoop* toolLoop = create_tool_loop(
     editor,
     UIContext::instance(),
+    pointer.button(),
     (drawingType == DrawingType::LineFreehand));
   if (!toolLoop)
     return nullptr;
@@ -624,21 +625,26 @@ DrawingState* StandbyState::startDrawingState(Editor* editor,
   return static_cast<DrawingState*>(newState.get());
 }
 
-bool StandbyState::checkStartDrawingStraightLine(Editor* editor)
+bool StandbyState::checkStartDrawingStraightLine(Editor* editor,
+                                                 const ui::MouseMessage* msg)
 {
   // Start line preview with shift key
-  if (editor->startStraightLineWithFreehandTool()) {
+  if (editor->startStraightLineWithFreehandTool(msg)) {
+    tools::Pointer::Button pointerButton =
+      (msg ? button_from_msg(msg): tools::Pointer::Left);
+
     DrawingState* drawingState =
       startDrawingState(editor,
                         DrawingType::LineFreehand,
                         tools::Pointer(
                           editor->document()->lastDrawingPoint(),
-                          tools::Pointer::Left));
+                          pointerButton));
     if (drawingState) {
       drawingState->sendMovementToToolLoop(
         tools::Pointer(
-          editor->screenToEditor(ui::get_mouse_position()),
-          tools::Pointer::Left));
+          editor->screenToEditor(msg ? msg->position():
+                                       ui::get_mouse_position()),
+          pointerButton));
       return true;
     }
   }

src/app/ui/editor/standby_state.h

@@ -50,7 +50,7 @@ namespace app {
 
   protected:
     void callEyedropper(Editor* editor);
-    bool checkStartDrawingStraightLine(Editor* editor);
+    bool checkStartDrawingStraightLine(Editor* editor, const ui::MouseMessage* msg);
 
     class Decorator : public EditorDecorator {
     public:

src/app/ui/editor/tool_loop_impl.cpp

@@ -543,6 +543,7 @@ public:
 tools::ToolLoop* create_tool_loop(
   Editor* editor,
   Context* context,
+  const tools::Pointer::Button button,
   const bool convertLineToFreehand)
 {
   tools::Tool* tool = editor->getCurrentEditorTool();
@@ -562,7 +563,7 @@ tools::ToolLoop* create_tool_loop(
   // isFloodFill) because we need the original layer source
   // image/pixels to stop the flood-fill algorithm.
   if (ink->isSelection() &&
-      !tool->getPointShape(editor->isSecondaryButton() ? 1: 0)->isFloodFill()) {
+      !tool->getPointShape(button != tools::Pointer::Left ? 1: 0)->isFloodFill()) {
     layer = nullptr;
   }
   else {
@@ -603,15 +604,15 @@ tools::ToolLoop* create_tool_loop(
 
   // Create the new tool loop
   try {
-    tools::ToolLoop::Button button =
-      (!editor->isSecondaryButton() ? tools::ToolLoop::Left:
-                                      tools::ToolLoop::Right);
+    tools::ToolLoop::Button toolLoopButton =
+      (button == tools::Pointer::Left ? tools::ToolLoop::Left:
+                                        tools::ToolLoop::Right);
 
     tools::Controller* controller =
       (convertLineToFreehand ?
        App::instance()->toolBox()->getControllerById(
          tools::WellKnownControllers::LineFreehand):
-       tool->getController(button));
+       tool->getController(toolLoopButton));
 
     const bool saveLastPoint =
       (ink->isPaint() &&
@@ -624,7 +625,7 @@ tools::ToolLoop* create_tool_loop(
       ink,
       controller,
       editor->document(),
-      button,
+      toolLoopButton,
       fg, bg,
       saveLastPoint);
   }

src/app/ui/editor/tool_loop_impl.h

@@ -8,6 +8,7 @@
 #define APP_UI_EDITOR_TOOL_LOOP_IMPL_H_INCLUDED
 #pragma once
 
+#include "app/tools/pointer.h"
 #include "doc/image_ref.h"
 #include "gfx/fwd.h"
 
@@ -26,6 +27,7 @@ namespace app {
   tools::ToolLoop* create_tool_loop(
     Editor* editor,
     Context* context,
+    const tools::Pointer::Button button,
     const bool convertLineToFreehand);
 
   tools::ToolLoop* create_tool_loop_preview(