Internal: Scrollbar: Extracted scrollbar code for other uses (eg. table v2 scrolling without using a child window).

This commit is contained in:
omar 2019-05-09 19:05:36 +02:00
parent 9534ef9b26
commit 37174c85e2
2 changed files with 111 additions and 101 deletions

View File

@ -956,7 +956,7 @@ struct ImGuiContext
bool DragCurrentAccumDirty;
float DragCurrentAccum; // Accumulator for dragging modification. Always high-precision, not rounded by end-user precision settings
float DragSpeedDefaultRatio; // If speed == 0.0f, uses (max-min) * DragSpeedDefaultRatio
ImVec2 ScrollbarClickDeltaToGrabCenter; // Distance between mouse and center of grab box, normalized in parent space. Use storage?
float ScrollbarClickDeltaToGrabCenter; // Distance between mouse and center of grab box, normalized in parent space. Use storage?
int TooltipOverrideCount;
ImVector<char> PrivateClipboard; // If no custom clipboard handler is defined
@ -1092,7 +1092,7 @@ struct ImGuiContext
DragCurrentAccumDirty = false;
DragCurrentAccum = 0.0f;
DragSpeedDefaultRatio = 1.0f / 100.0f;
ScrollbarClickDeltaToGrabCenter = ImVec2(0.0f, 0.0f);
ScrollbarClickDeltaToGrabCenter = 0.0f;
TooltipOverrideCount = 0;
MultiSelectScopeId = 0;
@ -1551,6 +1551,7 @@ namespace ImGui
IMGUI_API bool CollapseButton(ImGuiID id, const ImVec2& pos);
IMGUI_API bool ArrowButtonEx(const char* str_id, ImGuiDir dir, ImVec2 size_arg, ImGuiButtonFlags flags);
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 ImGuiID GetScrollbarID(ImGuiWindow* window, ImGuiAxis axis);
IMGUI_API void SeparatorEx(ImGuiSeparatorFlags flags);

View File

@ -380,6 +380,7 @@ void ImGui::BulletTextV(const char* fmt, va_list args)
// - ArrowButton()
// - CloseButton() [Internal]
// - CollapseButton() [Internal]
// - ScrollbarEx() [Internal]
// - Scrollbar() [Internal]
// - Image()
// - ImageButton()
@ -777,6 +778,98 @@ ImGuiID ImGui::GetScrollbarID(ImGuiWindow* window, ImGuiAxis axis)
// - 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.
// Still, the code should probably be made simpler..
bool ImGui::ScrollbarEx(const ImRect& bb_frame, ImGuiID id, ImGuiAxis axis, float* p_scroll_v, float size_avail_v, float size_contents_v, ImDrawCornerFlags rounding_corners)
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
if (window->SkipItems)
return false;
const float bb_frame_width = bb_frame.GetWidth();
const float bb_frame_height = bb_frame.GetHeight();
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)
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));
if (alpha <= 0.0f)
return false;
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((float)(int)((bb_frame_width - 2.0f) * 0.5f), 0.0f, 3.0f), -ImClamp((float)(int)((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();
// 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(size_contents_v, 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(size_contents_v, size_avail_v), 1.0f);
const float grab_h_pixels = ImClamp(scrollbar_size_v * (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;
ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_NoNavFocus);
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;
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;
// 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 (g.ActiveIdIsJustActivated)
{
// On initial click calculate the distance between mouse and the center of the grab
seek_absolute = (clicked_v_norm < grab_v_norm || clicked_v_norm > grab_v_norm + grab_h_norm);
if (seek_absolute)
g.ScrollbarClickDeltaToGrabCenter = 0.0f;
else
g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5f;
}
// 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 - g.ScrollbarClickDeltaToGrabCenter - grab_h_norm * 0.5f) / (1.0f - grab_h_norm));
*p_scroll_v = (float)(int)(0.5f + scroll_v_norm * scroll_max);//(win_size_contents_v - win_size_v));
// Update values for rendering
scroll_ratio = ImSaturate(*p_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)
g.ScrollbarClickDeltaToGrabCenter = clicked_v_norm - grab_v_norm - grab_h_norm * 0.5f;
}
// Render
window->DrawList->AddRectFilled(bb_frame.Min, bb_frame.Max, GetColorU32(ImGuiCol_ScrollbarBg), window->WindowRounding, rounding_corners);
const ImU32 grab_col = GetColorU32(held ? ImGuiCol_ScrollbarGrabActive : hovered ? ImGuiCol_ScrollbarGrabHovered : ImGuiCol_ScrollbarGrab, alpha);
ImRect grab_rect;
if (horizontal)
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);
window->DrawList->AddRectFilled(grab_rect.Min, grab_rect.Max, grab_col, style.ScrollbarRounding);
return held;
}
void ImGui::Scrollbar(ImGuiAxis axis)
{
ImGuiContext& g = *GImGui;
@ -787,115 +880,31 @@ void ImGui::Scrollbar(ImGuiAxis axis)
const ImGuiID id = GetScrollbarID(window, axis);
KeepAliveID(id);
// Render background
bool other_scrollbar = (horizontal ? window->ScrollbarY : window->ScrollbarX);
float other_scrollbar_size_w = other_scrollbar ? style.ScrollbarSize : 0.0f;
const ImRect host_rect = window->Rect();
// Calculate our bounding box (FIXME: This is messy, should be made simpler using e.g. InnerRect/WorkRect data).
const float other_scrollbar_size = window->ScrollbarSizes[axis];
const ImRect win_rect = window->Rect();
const float border_size = window->WindowBorderSize;
ImRect bb = horizontal
? ImRect(host_rect.Min.x + border_size, host_rect.Max.y - style.ScrollbarSize, host_rect.Max.x - other_scrollbar_size_w - border_size, host_rect.Max.y - border_size)
: ImRect(host_rect.Max.x - style.ScrollbarSize, host_rect.Min.y + border_size, host_rect.Max.x - border_size, host_rect.Max.y - other_scrollbar_size_w - border_size);
bb.Min.x = ImMax(host_rect.Min.x, bb.Min.x); // Handle case where the host rectangle is smaller than the scrollbar
bb.Min.y = ImMax(host_rect.Min.y, bb.Min.y);
? ImRect(win_rect.Min.x + border_size, win_rect.Max.y - style.ScrollbarSize, win_rect.Max.x - other_scrollbar_size - border_size, win_rect.Max.y - border_size)
: ImRect(win_rect.Max.x - style.ScrollbarSize, win_rect.Min.y + border_size, win_rect.Max.x - border_size, win_rect.Max.y - other_scrollbar_size - border_size);
bb.Min.x = ImMax(win_rect.Min.x, bb.Min.x); // Handle case where the host rectangle is smaller than the scrollbar
bb.Min.y = ImMax(win_rect.Min.y, bb.Min.y);
if (!horizontal)
bb.Min.y += window->TitleBarHeight() + ((window->Flags & ImGuiWindowFlags_MenuBar) ? window->MenuBarHeight() : 0.0f); // FIXME: InnerRect?
const float bb_width = bb.GetWidth();
const float bb_height = bb.GetHeight();
if (bb_width <= 0.0f || bb_height <= 0.0f)
return;
// 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)
float alpha = 1.0f;
if ((axis == ImGuiAxis_Y) && bb_height < g.FontSize + g.Style.FramePadding.y * 2.0f)
{
alpha = ImSaturate((bb_height - g.FontSize) / (g.Style.FramePadding.y * 2.0f));
if (alpha <= 0.0f)
return;
}
const bool allow_interaction = (alpha >= 1.0f);
int window_rounding_corners;
// Select rounding
ImDrawCornerFlags rounding_corners;
if (horizontal)
window_rounding_corners = ImDrawCornerFlags_BotLeft | (other_scrollbar ? 0 : ImDrawCornerFlags_BotRight);
rounding_corners = ImDrawCornerFlags_BotLeft;
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_width - 2.0f) * 0.5f), 0.0f, 3.0f), -ImClamp((float)(int)((bb_height - 2.0f) * 0.5f), 0.0f, 3.0f)));
rounding_corners = ((window->Flags & ImGuiWindowFlags_NoTitleBar) && !(window->Flags & ImGuiWindowFlags_MenuBar)) ? ImDrawCornerFlags_TopRight : 0;
if (other_scrollbar_size <= 0.0f)
rounding_corners |= ImDrawCornerFlags_BotRight;
// 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 && 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* 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 grab
const ImU32 grab_col = GetColorU32(held ? ImGuiCol_ScrollbarGrabActive : hovered ? ImGuiCol_ScrollbarGrabHovered : ImGuiCol_ScrollbarGrab, alpha);
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, host_rect.Max.x), bb.Max.y);
ScrollbarEx(bb, id, axis, &window->Scroll.x, window->SizeFull.x - other_scrollbar_size, window->SizeContents.x, rounding_corners);
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, host_rect.Max.y));
window->DrawList->AddRectFilled(grab_rect.Min, grab_rect.Max, grab_col, style.ScrollbarRounding);
ScrollbarEx(bb, id, axis, &window->Scroll.y, window->SizeFull.y - other_scrollbar_size, window->SizeContents.y, 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)