From f7852fa8e8175405f66cb4bce0cd0a85e4cebff8 Mon Sep 17 00:00:00 2001 From: omar Date: Fri, 10 Apr 2020 11:03:22 +0200 Subject: [PATCH] Internals: Extracted GetWindowScrollbarRect() out of Scrollbar() and tidying up code to make it more obvious how to draw over scrollbars. (#3114) --- imgui_internal.h | 3 +- imgui_widgets.cpp | 97 +++++++++++++++++++++++++++-------------------- 2 files changed, 57 insertions(+), 43 deletions(-) diff --git a/imgui_internal.h b/imgui_internal.h index 7e744b3f..61c1e5b7 100644 --- a/imgui_internal.h +++ b/imgui_internal.h @@ -1477,7 +1477,7 @@ struct IMGUI_API ImGuiWindow ImVec2 ScrollMax; ImVec2 ScrollTarget; // target scroll position. stored as cursor position with scrolling canceled out, so the highest point is always 0.0f. (FLT_MAX for no change) ImVec2 ScrollTargetCenterRatio; // 0.0f = scroll so that target position is at top, 0.5f = scroll so that target position is centered - ImVec2 ScrollbarSizes; // Size taken by scrollbars on each axis + ImVec2 ScrollbarSizes; // Size taken by each scrollbars on their smaller axis. Pay attention! ScrollbarSizes.x == width of the vertical scrollbar, ScrollbarSizes.y = height of the horizontal scrollbar. bool ScrollbarX, ScrollbarY; // Are scrollbars visible? bool Active; // Set to true on Begin(), unless Collapsed bool WasActive; @@ -1847,6 +1847,7 @@ namespace ImGui IMGUI_API bool ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size_arg, ImGuiButtonFlags flags = 0); IMGUI_API void Scrollbar(ImGuiAxis axis); IMGUI_API bool ScrollbarEx(const ImRect& bb, ImGuiID id, ImGuiAxis axis, float* p_scroll_v, float avail_v, float contents_v, ImDrawCornerFlags rounding_corners); + IMGUI_API ImRect GetWindowScrollbarRect(ImGuiWindow* window, ImGuiAxis axis); IMGUI_API ImGuiID GetWindowScrollbarID(ImGuiWindow* window, ImGuiAxis axis); IMGUI_API ImGuiID GetWindowResizeID(ImGuiWindow* window, int n); // 0..3: corners, 4..7: borders IMGUI_API void SeparatorEx(ImGuiSeparatorFlags flags); diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp index a0bfdd6c..33a98635 100644 --- a/imgui_widgets.cpp +++ b/imgui_widgets.cpp @@ -391,8 +391,10 @@ void ImGui::BulletTextV(const char* fmt, va_list args) // - ArrowButton() // - CloseButton() [Internal] // - CollapseButton() [Internal] -// - ScrollbarEx() [Internal] +// - GetWindowScrollbarID() [Internal] +// - GetWindowScrollbarRect() [Internal] // - Scrollbar() [Internal] +// - ScrollbarEx() [Internal] // - Image() // - ImageButton() // - Checkbox() @@ -812,6 +814,49 @@ ImGuiID ImGui::GetWindowScrollbarID(ImGuiWindow* window, ImGuiAxis axis) return window->GetIDNoKeepAlive(axis == ImGuiAxis_X ? "#SCROLLX" : "#SCROLLY"); } +// Return scrollbar rectangle, must only be called for corresponding axis if window->ScrollbarX/Y is set. +ImRect ImGui::GetWindowScrollbarRect(ImGuiWindow* window, ImGuiAxis axis) +{ + const ImRect outer_rect = window->Rect(); + const ImRect inner_rect = window->InnerRect; + const float border_size = window->WindowBorderSize; + const float scrollbar_size = window->ScrollbarSizes[axis ^ 1]; // (ScrollbarSizes.x = width of Y scrollbar; ScrollbarSizes.y = height of X scrollbar) + IM_ASSERT(scrollbar_size > 0.0f); + if (axis == ImGuiAxis_X) + return ImRect(inner_rect.Min.x, ImMax(outer_rect.Min.y, outer_rect.Max.y - border_size - scrollbar_size), inner_rect.Max.x, outer_rect.Max.y); + else + return ImRect(ImMax(outer_rect.Min.x, outer_rect.Max.x - border_size - scrollbar_size), inner_rect.Min.y, outer_rect.Max.x, inner_rect.Max.y); +} + +void ImGui::Scrollbar(ImGuiAxis axis) +{ + ImGuiContext& g = *GImGui; + ImGuiWindow* window = g.CurrentWindow; + + const ImGuiID id = GetWindowScrollbarID(window, axis); + KeepAliveID(id); + + // Calculate scrollbar bounding box + ImRect bb = GetWindowScrollbarRect(window, axis); + ImDrawCornerFlags rounding_corners = 0; + if (axis == ImGuiAxis_X) + { + rounding_corners |= ImDrawCornerFlags_BotLeft; + if (!window->ScrollbarY) + rounding_corners |= ImDrawCornerFlags_BotRight; + } + else + { + if ((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar)) + rounding_corners |= ImDrawCornerFlags_TopRight; + if (!window->ScrollbarX) + rounding_corners |= ImDrawCornerFlags_BotRight; + } + float size_avail = window->InnerRect.Max[axis] - window->InnerRect.Min[axis]; + float size_contents = window->ContentSize[axis] + window->WindowPadding[axis] * 2.0f; + ScrollbarEx(bb, id, axis, &window->Scroll[axis], size_avail, size_contents, rounding_corners); +} + // Vertical/Horizontal 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) @@ -830,7 +875,7 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa if (bb_frame_width <= 0.0f || bb_frame_height <= 0.0f) return false; - // When we are too small, start hiding and disabling the grab (this reduce visual noise on very small window and facilitate using the resize grab) + // When we are too small, start hiding and disabling the grab (this reduce visual noise on very small window and facilitate using the window resize grab) float alpha = 1.0f; if ((axis == ImGuiAxis_Y) && bb_frame_height < g.FontSize + g.Style.FramePadding.y * 2.0f) alpha = ImSaturate((bb_frame_height - g.FontSize) / (g.Style.FramePadding.y * 2.0f)); @@ -839,13 +884,12 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa const ImGuiStyle& style = g.Style; const bool allow_interaction = (alpha >= 1.0f); - const bool horizontal = (axis == ImGuiAxis_X); ImRect bb = bb_frame; bb.Expand(ImVec2(-ImClamp(IM_FLOOR((bb_frame_width - 2.0f) * 0.5f), 0.0f, 3.0f), -ImClamp(IM_FLOOR((bb_frame_height - 2.0f) * 0.5f), 0.0f, 3.0f))); // V denote the main, longer axis of the scrollbar (= height for a vertical scrollbar) - const float scrollbar_size_v = horizontal ? bb.GetWidth() : bb.GetHeight(); + const float scrollbar_size_v = (axis == ImGuiAxis_X) ? bb.GetWidth() : bb.GetHeight(); // 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. @@ -861,11 +905,11 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa float scroll_max = ImMax(1.0f, size_contents_v - size_avail_v); float scroll_ratio = ImSaturate(*p_scroll_v / scroll_max); - float grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v; + float grab_v_norm = scroll_ratio * (scrollbar_size_v - grab_h_pixels) / scrollbar_size_v; // Grab position in normalized space if (held && allow_interaction && 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 scrollbar_pos_v = bb.Min[axis]; + float mouse_pos_v = g.IO.MousePos[axis]; // 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); @@ -882,7 +926,7 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5f; } - // Apply scroll + // Apply scroll (p_scroll_v will generally point on one member of window->Scroll) // It is ok to modify Scroll here because we are being called in Begin() after the calculation of ContentSize and before setting up our starting position const float scroll_v_norm = ImSaturate((clicked_v_norm - g.ScrollbarClickDeltaToGrabCenter - grab_h_norm * 0.5f) / (1.0f - grab_h_norm)); *p_scroll_v = IM_ROUND(scroll_v_norm * scroll_max);//(win_size_contents_v - win_size_v)); @@ -897,10 +941,11 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa } // Render - window->DrawList->AddRectFilled(bb_frame.Min, bb_frame.Max, GetColorU32(ImGuiCol_ScrollbarBg), window->WindowRounding, rounding_corners); + const ImU32 bg_col = GetColorU32(ImGuiCol_ScrollbarBg); const ImU32 grab_col = GetColorU32(held ? ImGuiCol_ScrollbarGrabActive : hovered ? ImGuiCol_ScrollbarGrabHovered : ImGuiCol_ScrollbarGrab, alpha); + window->DrawList->AddRectFilled(bb_frame.Min, bb_frame.Max, bg_col, window->WindowRounding, rounding_corners); ImRect grab_rect; - if (horizontal) + if (axis == ImGuiAxis_X) grab_rect = ImRect(ImLerp(bb.Min.x, bb.Max.x, grab_v_norm), bb.Min.y, ImLerp(bb.Min.x, bb.Max.x, grab_v_norm) + grab_h_pixels, bb.Max.y); else grab_rect = ImRect(bb.Min.x, ImLerp(bb.Min.y, bb.Max.y, grab_v_norm), bb.Max.x, ImLerp(bb.Min.y, bb.Max.y, grab_v_norm) + grab_h_pixels); @@ -909,38 +954,6 @@ bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, floa return held; } -void ImGui::Scrollbar(ImGuiAxis axis) -{ - ImGuiContext& g = *GImGui; - ImGuiWindow* window = g.CurrentWindow; - - const ImGuiID id = GetWindowScrollbarID(window, axis); - KeepAliveID(id); - - // Calculate scrollbar bounding box - const ImRect outer_rect = window->Rect(); - const ImRect inner_rect = window->InnerRect; - const float border_size = window->WindowBorderSize; - const float scrollbar_size = window->ScrollbarSizes[axis ^ 1]; - IM_ASSERT(scrollbar_size > 0.0f); - const float other_scrollbar_size = window->ScrollbarSizes[axis]; - ImDrawCornerFlags rounding_corners = (other_scrollbar_size <= 0.0f) ? ImDrawCornerFlags_BotRight : 0; - ImRect bb; - if (axis == ImGuiAxis_X) - { - bb.Min = ImVec2(inner_rect.Min.x, ImMax(outer_rect.Min.y, outer_rect.Max.y - border_size - scrollbar_size)); - bb.Max = ImVec2(inner_rect.Max.x, outer_rect.Max.y); - rounding_corners |= ImDrawCornerFlags_BotLeft; - } - else - { - bb.Min = ImVec2(ImMax(outer_rect.Min.x, outer_rect.Max.x - border_size - scrollbar_size), inner_rect.Min.y); - bb.Max = ImVec2(outer_rect.Max.x, window->InnerRect.Max.y); - rounding_corners |= ((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar)) ? ImDrawCornerFlags_TopRight : 0; - } - ScrollbarEx(bb, id, axis, &window->Scroll[axis], inner_rect.Max[axis] - inner_rect.Min[axis], window->ContentSize[axis] + window->WindowPadding[axis] * 2.0f, rounding_corners); -} - void ImGui::Image(ImTextureID user_texture_id, const ImVec2& size, const ImVec2& uv0, const ImVec2& uv1, const ImVec4& tint_col, const ImVec4& border_col) { ImGuiWindow* window = GetCurrentWindow();