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Scrollbar: moved from Begin() into its own Scrollbar() function + tidying up

This commit is contained in:
ocornut 2015-03-08 16:37:03 +00:00
parent f021080851
commit 6e12d31417
1 changed files with 71 additions and 65 deletions
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136
imgui.cpp
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@ -437,6 +437,7 @@ static bool IsClipped(const ImGuiAabb& bb);
static bool IsMouseHoveringBox(const ImGuiAabb& bb);
static bool IsKeyPressedMap(ImGuiKey key, bool repeat = true);
static void Scrollbar(ImGuiWindow* window);
static bool CloseWindowButton(bool* p_opened = NULL);
static void FocusWindow(ImGuiWindow* window);
static ImGuiWindow* FindHoveredWindow(ImVec2 pos, bool excluding_childs);
@ -3026,71 +3027,7 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size, float bg
// Scrollbar
if (window->ScrollbarY)
{
// Render background
ImGuiAabb scrollbar_bb(window->Aabb().Max.x - style.ScrollbarWidth, title_bar_aabb.Max.y+1, window->Aabb().Max.x, window->Aabb().Max.y-1);
window->DrawList->AddRectFilled(scrollbar_bb.Min, scrollbar_bb.Max, window->Color(ImGuiCol_ScrollbarBg));
scrollbar_bb.Expand(ImVec2(-3,-3));
// The entire piece of code below is rather confusing because:
// - The grabable box size 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.
// - We handle absolute seeking (when first clicking outside the grab) and relative manipulation (afterward or when clicking inside the grab)
// - We store values as ratio and in a form that allows the window content to change while we are holding on a scrollbar
const float scroll_max = ImMax(1.0f, window->SizeContents.y - window->Size.y);
const float scrollbar_height = scrollbar_bb.GetHeight();
const float grab_size_y_pixels = ImMax(style.GrabMinSize, scrollbar_height * ImSaturate(window->Size.y / ImMax(window->SizeContents.y, window->Size.y)));
const float grab_size_y_norm = grab_size_y_pixels / scrollbar_height;
// Handle input right away (none of the code of Begin() above is relying on scrolling position)
bool held = false;
bool hovered = false;
const ImGuiID scrollbar_id = window->GetID("#SCROLLY");
const bool previously_held = (g.ActiveId == scrollbar_id);
ButtonBehaviour(scrollbar_bb, scrollbar_id, &hovered, &held, true);
float scroll_ratio = ImSaturate(window->ScrollY / scroll_max);
float grab_pos_y_norm = scroll_ratio * (scrollbar_height - grab_size_y_pixels) / scrollbar_height;
if (held)
{
const float clicked_y_norm = ImSaturate((g.IO.MousePos.y - scrollbar_bb.Min.y) / scrollbar_height); // Click position in scrollbar space (0.0f->1.0f)
g.HoveredId = scrollbar_id;
bool seek_absolute = false;
if (!previously_held)
{
// On initial click calculate the distance between mouse and the center of the grab
if (clicked_y_norm >= grab_pos_y_norm && clicked_y_norm <= grab_pos_y_norm + grab_size_y_norm)
{
g.ScrollbarClickDeltaToGrabCenter = clicked_y_norm - grab_pos_y_norm - grab_size_y_norm*0.5f;
}
else
{
seek_absolute = true;
g.ScrollbarClickDeltaToGrabCenter = 0;
}
}
// Apply scroll
const float scroll_y_norm = ImSaturate((clicked_y_norm - g.ScrollbarClickDeltaToGrabCenter - grab_size_y_norm*0.5f) / (1.0f - grab_size_y_norm));
window->ScrollY = (float)(int)(0.5f + scroll_y_norm * (window->SizeContents.y - window->Size.y));
window->NextScrollY = window->ScrollY;
// Update values for rendering
scroll_ratio = ImSaturate(window->ScrollY / scroll_max);
grab_pos_y_norm = scroll_ratio * (scrollbar_height - grab_size_y_pixels) / scrollbar_height;
// Update distance to grab now that we have seeked and saturated
if (seek_absolute)
g.ScrollbarClickDeltaToGrabCenter = clicked_y_norm - grab_pos_y_norm - grab_size_y_norm*0.5f;
}
// Render
const ImU32 grab_col = window->Color(held ? ImGuiCol_ScrollbarGrabActive : hovered ? ImGuiCol_ScrollbarGrabHovered : ImGuiCol_ScrollbarGrab);
window->DrawList->AddRectFilled(
ImVec2(scrollbar_bb.Min.x, ImLerp(scrollbar_bb.Min.y, scrollbar_bb.Max.y, grab_pos_y_norm)),
ImVec2(scrollbar_bb.Max.x, ImLerp(scrollbar_bb.Min.y, scrollbar_bb.Max.y, grab_pos_y_norm) + grab_size_y_pixels), grab_col);
}
Scrollbar(window);
// Render resize grip
// (after the input handling so we don't have a frame of latency)
@ -3216,6 +3153,75 @@ void ImGui::End()
g.CurrentWindow = 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 ratio and in a form that allows the window content to change while we are holding on a scrollbar
static void Scrollbar(ImGuiWindow* window)
{
ImGuiState& g = *GImGui;
const ImGuiStyle& style = g.Style;
const ImGuiID id = window->GetID("#SCROLLY");
// Render background
ImGuiAabb bb(window->Aabb().Max.x - style.ScrollbarWidth, window->Pos.y + window->TitleBarHeight()+1, window->Aabb().Max.x, window->Aabb().Max.y-1);
window->DrawList->AddRectFilled(bb.Min, bb.Max, window->Color(ImGuiCol_ScrollbarBg));
bb.Expand(ImVec2(-3,-3));
const float scrollbar_height = bb.GetHeight();
// The grabable box size 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.
const float grab_h_pixels = ImMax(style.GrabMinSize, scrollbar_height * ImSaturate(window->Size.y / ImMax(window->SizeContents.y, window->Size.y)));
const float grab_h_norm = grab_h_pixels / scrollbar_height;
// 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);
ButtonBehaviour(bb, id, &hovered, &held, true);
const float scroll_max = ImMax(1.0f, window->SizeContents.y - window->Size.y);
float scroll_ratio = ImSaturate(window->ScrollY / scroll_max);
float grab_y_norm = scroll_ratio * (scrollbar_height - grab_h_pixels) / scrollbar_height;
if (held)
{
const float clicked_y_norm = ImSaturate((g.IO.MousePos.y - bb.Min.y) / scrollbar_height); // Click position in scrollbar space (0.0f->1.0f)
g.HoveredId = id;
bool seek_absolute = false;
if (!previously_held)
{
// On initial click calculate the distance between mouse and the center of the grab
if (clicked_y_norm >= grab_y_norm && clicked_y_norm <= grab_y_norm + grab_h_norm)
{
g.ScrollbarClickDeltaToGrabCenter = clicked_y_norm - grab_y_norm - grab_h_norm*0.5f;
}
else
{
seek_absolute = true;
g.ScrollbarClickDeltaToGrabCenter = 0;
}
}
// Apply scroll
const float scroll_y_norm = ImSaturate((clicked_y_norm - g.ScrollbarClickDeltaToGrabCenter - grab_h_norm*0.5f) / (1.0f - grab_h_norm));
window->ScrollY = (float)(int)(0.5f + scroll_y_norm * (window->SizeContents.y - window->Size.y));
window->NextScrollY = window->ScrollY;
// Update values for rendering
scroll_ratio = ImSaturate(window->ScrollY / scroll_max);
grab_y_norm = scroll_ratio * (scrollbar_height - grab_h_pixels) / scrollbar_height;
// Update distance to grab now that we have seeked and saturated
if (seek_absolute)
g.ScrollbarClickDeltaToGrabCenter = clicked_y_norm - grab_y_norm - grab_h_norm*0.5f;
}
// Render
const ImU32 grab_col = window->Color(held ? ImGuiCol_ScrollbarGrabActive : hovered ? ImGuiCol_ScrollbarGrabHovered : ImGuiCol_ScrollbarGrab);
window->DrawList->AddRectFilled(ImVec2(bb.Min.x, ImLerp(bb.Min.y, bb.Max.y, grab_y_norm)), ImVec2(bb.Max.x, ImLerp(bb.Min.y, bb.Max.y, grab_y_norm) + grab_h_pixels), grab_col);
}
// Moving window to front of display (which happens to be back of our sorted list)
static void FocusWindow(ImGuiWindow* window)
{