Scrolling, Nav: Fixed programmatic scroll leading to a slightly incorrect scroll offset when the window has decorations or a menu-bar (broken in 1.71). This was mostly noticeable when a keyboard/gamepad movement led to scrolling the view, or using e.g. SetScrollHereY() function. Fix/amend a0994d74.

This commit is contained in:
omar 2019-07-31 10:26:10 -07:00
parent 3548fb8013
commit 4cfaf7d89c
4 changed files with 53 additions and 32 deletions

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@ -33,6 +33,12 @@ HOW TO UPDATE?
VERSION 1.73 (In Progress)
-----------------------------------------------------------------------
Other Changes:
- Scrolling, Nav: Fixed programmatic scroll leading to a slightly incorrect scroll offset when
the window has decorations or a menu-bar (broken in 1.71). This was mostly noticeable when
a keyboard/gamepad movement led to scrolling the view, or using e.g. SetScrollHereY() function.
-----------------------------------------------------------------------
VERSION 1.72 (Released 2019-07-27)

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@ -5692,7 +5692,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
// Inner rectangle
// Not affected by window border size. Used by:
// - InnerClipRect
// - NavScrollToBringItemIntoView()
// - ScrollToBringRectIntoView()
// - NavUpdatePageUpPageDown()
// - Scrollbar()
window->InnerRect.Min.x = window->Pos.x;
@ -7141,18 +7141,19 @@ static ImVec2 CalcNextScrollFromScrollTargetAndClamp(ImGuiWindow* window, bool s
target_x = 0.0f;
else if (snap_on_edges && cr_x >= 1.0f && target_x >= window->ContentSize.x + window->WindowPadding.x + g.Style.ItemSpacing.x)
target_x = window->ContentSize.x + window->WindowPadding.x * 2.0f;
scroll.x = target_x - cr_x * window->InnerRect.GetWidth();
scroll.x = target_x - cr_x * (window->SizeFull.x - window->ScrollbarSizes.x);
}
if (window->ScrollTarget.y < FLT_MAX)
{
// 'snap_on_edges' allows for a discontinuity at the edge of scrolling limits to take account of WindowPadding so that scrolling to make the last item visible scroll far enough to see the padding.
float decoration_up_height = window->TitleBarHeight() + window->MenuBarHeight();
float cr_y = window->ScrollTargetCenterRatio.y;
float target_y = window->ScrollTarget.y;
if (snap_on_edges && cr_y <= 0.0f && target_y <= window->WindowPadding.y)
target_y = 0.0f;
if (snap_on_edges && cr_y >= 1.0f && target_y >= window->ContentSize.y + window->WindowPadding.y + g.Style.ItemSpacing.y)
target_y = window->ContentSize.y + window->WindowPadding.y * 2.0f;
scroll.y = target_y - cr_y * window->InnerRect.GetHeight();
scroll.y = target_y - cr_y * (window->SizeFull.y - window->ScrollbarSizes.y - decoration_up_height);
}
scroll = ImMax(scroll, ImVec2(0.0f, 0.0f));
if (!window->Collapsed && !window->SkipItems)
@ -7164,7 +7165,7 @@ static ImVec2 CalcNextScrollFromScrollTargetAndClamp(ImGuiWindow* window, bool s
}
// Scroll to keep newly navigated item fully into view
void ImGui::ScrollToBringItemIntoView(ImGuiWindow* window, const ImRect& item_rect)
void ImGui::ScrollToBringRectIntoView(ImGuiWindow* window, const ImRect& item_rect)
{
ImRect window_rect(window->InnerRect.Min - ImVec2(1, 1), window->InnerRect.Max + ImVec2(1, 1));
//GetForegroundDrawList(window)->AddRect(window_rect.Min, window_rect.Max, IM_COL32_WHITE); // [DEBUG]
@ -7173,25 +7174,13 @@ void ImGui::ScrollToBringItemIntoView(ImGuiWindow* window, const ImRect& item_re
ImGuiContext& g = *GImGui;
if (window->ScrollbarX && item_rect.Min.x < window_rect.Min.x)
{
window->ScrollTarget.x = item_rect.Min.x - window->Pos.x + window->Scroll.x - g.Style.ItemSpacing.x;
window->ScrollTargetCenterRatio.x = 0.0f;
}
SetScrollFromPosX(window, item_rect.Min.x - window->Pos.x + g.Style.ItemSpacing.x, 0.0f);
else if (window->ScrollbarX && item_rect.Max.x >= window_rect.Max.x)
{
window->ScrollTarget.x = item_rect.Max.x - window->Pos.x + window->Scroll.x + g.Style.ItemSpacing.x;
window->ScrollTargetCenterRatio.x = 1.0f;
}
SetScrollFromPosX(window, item_rect.Max.x - window->Pos.x + g.Style.ItemSpacing.x, 1.0f);
if (item_rect.Min.y < window_rect.Min.y)
{
window->ScrollTarget.y = item_rect.Min.y - window->Pos.y + window->Scroll.y - g.Style.ItemSpacing.y;
window->ScrollTargetCenterRatio.y = 0.0f;
}
SetScrollFromPosY(window, item_rect.Min.y - window->Pos.y - g.Style.ItemSpacing.y, 0.0f);
else if (item_rect.Max.y >= window_rect.Max.y)
{
window->ScrollTarget.y = item_rect.Max.y - window->Pos.y + window->Scroll.y + g.Style.ItemSpacing.y;
window->ScrollTargetCenterRatio.y = 1.0f;
}
SetScrollFromPosY(window, item_rect.Max.y - window->Pos.y + g.Style.ItemSpacing.y, 1.0f);
}
float ImGui::GetScrollX()
@ -7244,26 +7233,37 @@ void ImGui::SetScrollY(ImGuiWindow* window, float new_scroll_y)
window->ScrollTargetCenterRatio.y = 0.0f;
}
void ImGui::SetScrollFromPosX(float local_x, float center_x_ratio)
void ImGui::SetScrollFromPosX(ImGuiWindow* window, float local_x, float center_x_ratio)
{
// We store a target position so centering can occur on the next frame when we are guaranteed to have a known window size
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
IM_ASSERT(center_x_ratio >= 0.0f && center_x_ratio <= 1.0f);
window->ScrollTarget.x = (float)(int)(local_x + window->Scroll.x);
window->ScrollTargetCenterRatio.x = center_x_ratio;
}
void ImGui::SetScrollFromPosY(float local_y, float center_y_ratio)
void ImGui::SetScrollFromPosY(ImGuiWindow* window, float local_y, float center_y_ratio)
{
// We store a target position so centering can occur on the next frame when we are guaranteed to have a known window size
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
IM_ASSERT(center_y_ratio >= 0.0f && center_y_ratio <= 1.0f);
const float decoration_up_height = window->TitleBarHeight() + window->MenuBarHeight();
local_y -= decoration_up_height;
window->ScrollTarget.y = (float)(int)(local_y + window->Scroll.y);
window->ScrollTargetCenterRatio.y = center_y_ratio;
}
void ImGui::SetScrollFromPosX(float local_x, float center_x_ratio)
{
ImGuiContext& g = *GImGui;
SetScrollFromPosX(g.CurrentWindow, local_x, center_x_ratio);
}
void ImGui::SetScrollFromPosY(float local_y, float center_y_ratio)
{
ImGuiContext& g = *GImGui;
SetScrollFromPosY(g.CurrentWindow, local_y, center_y_ratio);
}
// center_x_ratio: 0.0f left of last item, 0.5f horizontal center of last item, 1.0f right of last item.
void ImGui::SetScrollHereX(float center_x_ratio)
{
@ -8484,7 +8484,7 @@ static void ImGui::NavUpdateMoveResult()
if (g.NavLayer == 0)
{
ImRect rect_abs = ImRect(result->RectRel.Min + result->Window->Pos, result->RectRel.Max + result->Window->Pos);
ScrollToBringItemIntoView(result->Window, rect_abs);
ScrollToBringRectIntoView(result->Window, rect_abs);
// Estimate upcoming scroll so we can offset our result position so mouse position can be applied immediately after in NavUpdate()
ImVec2 next_scroll = CalcNextScrollFromScrollTargetAndClamp(result->Window, false);
@ -8493,7 +8493,7 @@ static void ImGui::NavUpdateMoveResult()
// Also scroll parent window to keep us into view if necessary (we could/should technically recurse back the whole the parent hierarchy).
if (result->Window->Flags & ImGuiWindowFlags_ChildWindow)
ScrollToBringItemIntoView(result->Window->ParentWindow, ImRect(rect_abs.Min + delta_scroll, rect_abs.Max + delta_scroll));
ScrollToBringRectIntoView(result->Window->ParentWindow, ImRect(rect_abs.Min + delta_scroll, rect_abs.Max + delta_scroll));
}
ClearActiveID();

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@ -2066,8 +2066,14 @@ static void ShowDemoWindowLayout()
static int track_item = 50;
static bool enable_track = true;
static bool enable_extra_decorations = false;
static float scroll_to_off_px = 0.0f;
static float scroll_to_pos_px = 200.0f;
ImGui::Checkbox("Decoration", &enable_extra_decorations);
ImGui::SameLine();
HelpMarker("We expose this for testing because scrolling sometimes had issues with window decoration such as menu-bars.");
ImGui::Checkbox("Track", &enable_track);
ImGui::PushItemWidth(100);
ImGui::SameLine(140); enable_track |= ImGui::DragInt("##item", &track_item, 0.25f, 0, 99, "Item = %d");
@ -2076,7 +2082,7 @@ static void ShowDemoWindowLayout()
ImGui::SameLine(140); scroll_to_off |= ImGui::DragFloat("##off", &scroll_to_off_px, 1.00f, 0, 9999, "+%.0f px");
bool scroll_to_pos = ImGui::Button("Scroll To Pos");
ImGui::SameLine(140); scroll_to_pos |= ImGui::DragFloat("##pos", &scroll_to_pos_px, 1.00f, 0, 9999, "X/Y = %.0f px");
ImGui::SameLine(140); scroll_to_pos |= ImGui::DragFloat("##pos", &scroll_to_pos_px, 1.00f, -10, 9999, "X/Y = %.0f px");
ImGui::PopItemWidth();
if (scroll_to_off || scroll_to_pos)
@ -2094,7 +2100,13 @@ static void ShowDemoWindowLayout()
const char* names[] = { "Top", "25%", "Center", "75%", "Bottom" };
ImGui::TextUnformatted(names[i]);
ImGui::BeginChild(ImGui::GetID((void*)(intptr_t)i), ImVec2(child_w, 200.0f), true, ImGuiWindowFlags_None);
ImGuiWindowFlags child_flags = enable_extra_decorations ? ImGuiWindowFlags_MenuBar : 0;
ImGui::BeginChild(ImGui::GetID((void*)(intptr_t)i), ImVec2(child_w, 200.0f), true, child_flags);
if (ImGui::BeginMenuBar())
{
ImGui::TextUnformatted("abc");
ImGui::EndMenuBar();
}
if (scroll_to_off)
ImGui::SetScrollY(scroll_to_off_px);
if (scroll_to_pos)
@ -2126,7 +2138,8 @@ static void ShowDemoWindowLayout()
for (int i = 0; i < 5; i++)
{
float child_height = ImGui::GetTextLineHeight() + style.ScrollbarSize + style.WindowPadding.y * 2.0f;
ImGui::BeginChild(ImGui::GetID((void*)(intptr_t)i), ImVec2(-100, child_height), true, ImGuiWindowFlags_HorizontalScrollbar);
ImGuiWindowFlags child_flags = ImGuiWindowFlags_HorizontalScrollbar | (enable_extra_decorations ? ImGuiWindowFlags_AlwaysVerticalScrollbar : 0);
ImGui::BeginChild(ImGui::GetID((void*)(intptr_t)i), ImVec2(-100, child_height), true, child_flags);
if (scroll_to_off)
ImGui::SetScrollX(scroll_to_off_px);
if (scroll_to_pos)

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@ -1499,7 +1499,9 @@ namespace ImGui
// Scrolling
IMGUI_API void SetScrollX(ImGuiWindow* window, float new_scroll_x);
IMGUI_API void SetScrollY(ImGuiWindow* window, float new_scroll_y);
IMGUI_API void ScrollToBringItemIntoView(ImGuiWindow* window, const ImRect& item_rect);
IMGUI_API void SetScrollFromPosX(ImGuiWindow* window, float local_x, float center_x_ratio = 0.5f);
IMGUI_API void SetScrollFromPosY(ImGuiWindow* window, float local_y, float center_y_ratio = 0.5f);
IMGUI_API void ScrollToBringRectIntoView(ImGuiWindow* window, const ImRect& item_rect);
// Basic Accessors
inline ImGuiID GetItemID() { ImGuiContext& g = *GImGui; return g.CurrentWindow->DC.LastItemId; }