Support multi-line progress information rendering (#6909)

Makes situations like #6098 less confusing.

Old:

![image](https://github.com/user-attachments/assets/9eeabb5a-9f7b-41f7-8123-c001b2f576e8)

New:

![image](https://github.com/user-attachments/assets/215e75a9-87c8-4963-a0b2-aa1f1198af62)

src/slic3r/GUI/SlicingProgressNotification.cpp

@@ -31,14 +31,13 @@ void NotificationManager::SlicingProgressNotification::init()
  m_endlines.push_back(0);
  }
  if (m_lines_count >= 2) {
- m_lines_count = 3;
+ m_lines_count = std::min((size_t)3, m_lines_count);
  m_multiline = true;
- while (m_endlines.size() < 3)
+ while (m_endlines.size() < m_lines_count)
  m_endlines.push_back(m_endlines.back());
  }
  else {
- m_lines_count = 2;
- m_endlines.push_back(m_endlines.back());
+ m_lines_count = 1;
  m_multiline = false;
  }
  if (m_state == EState::Shown)
@@ -222,7 +221,7 @@ void NotificationManager::SlicingProgressNotification::render(GLCanvas3D& canvas
  const ImVec2 dailytips_child_window_padding = m_dailytips_panel->is_expanded() ? ImVec2(15.f, 10.f) * scale : ImVec2(15.f, 0.f) * scale;
  const ImVec2 bottom_padding = ImVec2(0.f, 0.f) * scale;
  const float progress_panel_width = (m_window_width - 2 * progress_child_window_padding.x);
- const float progress_panel_height = (58.0f * scale);
+ const float progress_panel_height = (58.0f * scale) + (m_lines_count - 1) * m_line_height;
  const float dailytips_panel_width = (m_window_width - 2 * dailytips_child_window_padding.x);
  const float gcodeviewer_height = wxGetApp().plater()->get_preview_canvas3D()->get_gcode_viewer().get_legend_height();
  //const float dailytips_panel_height = std::min(380.0f * scale, std::max(90.0f, (cnv_size.get_height() - gcodeviewer_height - progress_panel_height - dailytips_child_window_padding.y - initial_y - m_line_height * 4)));
@@ -272,11 +271,12 @@ void NotificationManager::SlicingProgressNotification::render(GLCanvas3D& canvas
  if (ImGui::BeginChild(child_name.c_str(), ImVec2(progress_panel_width, progress_panel_height), false, child_window_flags)) {
  ImVec2 child_window_pos = ImGui::GetWindowPos();
  ImVec2 button_size = ImVec2(38.f, 38.f) * scale;
- ImVec2 button_pos = child_window_pos + ImVec2(progress_panel_width - button_size.x, (progress_panel_height - button_size.y) / 2.0f);
  float margin_x = 8.0f * scale;
- ImVec2 progress_bar_pos = child_window_pos + ImVec2(0, progress_panel_height / 2.0f);
  ImVec2 progress_bar_size = ImVec2(progress_panel_width - button_size.x - margin_x, 4.0f * scale);
- ImVec2 text_pos = ImVec2(progress_bar_pos.x, progress_bar_pos.y - m_line_height * 1.2f);
+ float text_bottom = progress_bar_size.y + m_line_height * 1.2f + 7.f * scale;
+ ImVec2 progress_bar_pos = child_window_pos + ImVec2(0, progress_panel_height - text_bottom);
+ ImVec2 button_pos = child_window_pos + ImVec2(progress_panel_width - button_size.x, progress_panel_height - text_bottom - button_size.y / 2.0f);
+ ImVec2 text_pos = ImVec2(progress_bar_pos.x, progress_bar_pos.y - m_line_height * (1.2f + m_lines_count - 1));
 
  render_text(text_pos);
  render_close_button(button_pos, button_size);
@@ -353,9 +353,13 @@ void Slic3r::GUI::NotificationManager::SlicingProgressNotification::render_text(
  imgui.pop_bold_font();
  }
  if(m_sp_state == SlicingProgressState::SP_PROGRESS) {
- //one line text
- ImGui::SetCursorScreenPos(pos);
- imgui.text(m_text1.substr(0, m_endlines[0]).c_str());
+ // multi-line text
+ int last_end = 0;
+ for (auto i = 0; i < m_lines_count; i++) {
+ ImGui::SetCursorScreenPos(pos + ImVec2(0, i * m_line_height));
+ imgui.text(m_text1.substr(last_end, m_endlines[i] - last_end).c_str());
+ last_end = m_endlines[i];
+ }
  }
 }