Refactor: Moved Scrollbar function from imgui.cpp to imgui_widgets.cpp, added file index (#2036)

This commit is contained in:
omar
2018-08-30 20:42:50 +02:00
parent 728b2ef026
commit df37a156e8
3 changed files with 129 additions and 111 deletions

110
imgui.cpp
View File

@ -5508,116 +5508,6 @@ void ImGui::End()
SetCurrentWindow(g.CurrentWindowStack.empty() ? NULL : g.CurrentWindowStack.back());
}
// Vertical scrollbar
// The entire piece of code below is rather confusing because:
// - We handle absolute seeking (when first clicking outside the grab) and relative manipulation (afterward or when clicking inside the grab)
// - We store values as normalized ratio and in a form that allows the window content to change while we are holding on a scrollbar
// - We handle both horizontal and vertical scrollbars, which makes the terminology not ideal.
void ImGui::Scrollbar(ImGuiLayoutType direction)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
const bool horizontal = (direction == ImGuiLayoutType_Horizontal);
const ImGuiStyle& style = g.Style;
const ImGuiID id = window->GetID(horizontal ? "#SCROLLX" : "#SCROLLY");
// Render background
bool other_scrollbar = (horizontal ? window->ScrollbarY : window->ScrollbarX);
float other_scrollbar_size_w = other_scrollbar ? style.ScrollbarSize : 0.0f;
const ImRect window_rect = window->Rect();
const float border_size = window->WindowBorderSize;
ImRect bb = horizontal
? ImRect(window->Pos.x + border_size, window_rect.Max.y - style.ScrollbarSize, window_rect.Max.x - other_scrollbar_size_w - border_size, window_rect.Max.y - border_size)
: ImRect(window_rect.Max.x - style.ScrollbarSize, window->Pos.y + border_size, window_rect.Max.x - border_size, window_rect.Max.y - other_scrollbar_size_w - border_size);
if (!horizontal)
bb.Min.y += window->TitleBarHeight() + ((window->Flags & ImGuiWindowFlags_MenuBar) ? window->MenuBarHeight() : 0.0f);
if (bb.GetWidth() <= 0.0f || bb.GetHeight() <= 0.0f)
return;
int window_rounding_corners;
if (horizontal)
window_rounding_corners = ImDrawCornerFlags_BotLeft | (other_scrollbar ? 0 : ImDrawCornerFlags_BotRight);
else
window_rounding_corners = (((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar)) ? ImDrawCornerFlags_TopRight : 0) | (other_scrollbar ? 0 : ImDrawCornerFlags_BotRight);
window->DrawList->AddRectFilled(bb.Min, bb.Max, GetColorU32(ImGuiCol_ScrollbarBg), window->WindowRounding, window_rounding_corners);
bb.Expand(ImVec2(-ImClamp((float)(int)((bb.Max.x - bb.Min.x - 2.0f) * 0.5f), 0.0f, 3.0f), -ImClamp((float)(int)((bb.Max.y - bb.Min.y - 2.0f) * 0.5f), 0.0f, 3.0f)));
// V denote the main, longer axis of the scrollbar (= height for a vertical scrollbar)
float scrollbar_size_v = horizontal ? bb.GetWidth() : bb.GetHeight();
float scroll_v = horizontal ? window->Scroll.x : window->Scroll.y;
float win_size_avail_v = (horizontal ? window->SizeFull.x : window->SizeFull.y) - other_scrollbar_size_w;
float win_size_contents_v = horizontal ? window->SizeContents.x : window->SizeContents.y;
// Calculate the height of our grabbable box. It generally represent the amount visible (vs the total scrollable amount)
// But we maintain a minimum size in pixel to allow for the user to still aim inside.
IM_ASSERT(ImMax(win_size_contents_v, win_size_avail_v) > 0.0f); // Adding this assert to check if the ImMax(XXX,1.0f) is still needed. PLEASE CONTACT ME if this triggers.
const float win_size_v = ImMax(ImMax(win_size_contents_v, win_size_avail_v), 1.0f);
const float grab_h_pixels = ImClamp(scrollbar_size_v * (win_size_avail_v / win_size_v), style.GrabMinSize, scrollbar_size_v);
const float grab_h_norm = grab_h_pixels / scrollbar_size_v;
// Handle input right away. None of the code of Begin() is relying on scrolling position before calling Scrollbar().
bool held = false;
bool hovered = false;
const bool previously_held = (g.ActiveId == id);
ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_NoNavFocus);
float scroll_max = ImMax(1.0f, win_size_contents_v - win_size_avail_v);
float scroll_ratio = ImSaturate(scroll_v / scroll_max);
float grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v;
if (held && grab_h_norm < 1.0f)
{
float scrollbar_pos_v = horizontal ? bb.Min.x : bb.Min.y;
float mouse_pos_v = horizontal ? g.IO.MousePos.x : g.IO.MousePos.y;
float* click_delta_to_grab_center_v = horizontal ? &g.ScrollbarClickDeltaToGrabCenter.x : &g.ScrollbarClickDeltaToGrabCenter.y;
// Click position in scrollbar normalized space (0.0f->1.0f)
const float clicked_v_norm = ImSaturate((mouse_pos_v - scrollbar_pos_v) / scrollbar_size_v);
SetHoveredID(id);
bool seek_absolute = false;
if (!previously_held)
{
// On initial click calculate the distance between mouse and the center of the grab
if (clicked_v_norm >= grab_v_norm && clicked_v_norm <= grab_v_norm + grab_h_norm)
{
*click_delta_to_grab_center_v = clicked_v_norm - grab_v_norm - grab_h_norm*0.5f;
}
else
{
seek_absolute = true;
*click_delta_to_grab_center_v = 0.0f;
}
}
// Apply scroll
// It is ok to modify Scroll here because we are being called in Begin() after the calculation of SizeContents and before setting up our starting position
const float scroll_v_norm = ImSaturate((clicked_v_norm - *click_delta_to_grab_center_v - grab_h_norm*0.5f) / (1.0f - grab_h_norm));
scroll_v = (float)(int)(0.5f + scroll_v_norm * scroll_max);//(win_size_contents_v - win_size_v));
if (horizontal)
window->Scroll.x = scroll_v;
else
window->Scroll.y = scroll_v;
// Update values for rendering
scroll_ratio = ImSaturate(scroll_v / scroll_max);
grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v;
// Update distance to grab now that we have seeked and saturated
if (seek_absolute)
*click_delta_to_grab_center_v = clicked_v_norm - grab_v_norm - grab_h_norm*0.5f;
}
// Render
const ImU32 grab_col = GetColorU32(held ? ImGuiCol_ScrollbarGrabActive : hovered ? ImGuiCol_ScrollbarGrabHovered : ImGuiCol_ScrollbarGrab);
ImRect grab_rect;
if (horizontal)
grab_rect = ImRect(ImLerp(bb.Min.x, bb.Max.x, grab_v_norm), bb.Min.y, ImMin(ImLerp(bb.Min.x, bb.Max.x, grab_v_norm) + grab_h_pixels, window_rect.Max.x), bb.Max.y);
else
grab_rect = ImRect(bb.Min.x, ImLerp(bb.Min.y, bb.Max.y, grab_v_norm), bb.Max.x, ImMin(ImLerp(bb.Min.y, bb.Max.y, grab_v_norm) + grab_h_pixels, window_rect.Max.y));
window->DrawList->AddRectFilled(grab_rect.Min, grab_rect.Max, grab_col, style.ScrollbarRounding);
}
void ImGui::BringWindowToFront(ImGuiWindow* window)
{
ImGuiContext& g = *GImGui;