Demo: Log: Comments. Using clipper. Not linking with rand() anymore.
diff --git a/docs/TODO.txt b/docs/TODO.txt
index 4c2a203..8b60c05 100644
--- a/docs/TODO.txt
+++ b/docs/TODO.txt
@@ -31,6 +31,7 @@
- window: freeze window flag: if not focused/hovered, return false, render with previous ImDrawList. and/or reduce refresh rate.
- window: investigate better auto-positioning for new windows.
- window/child: the first draw command of a child window could be moved into the current draw command of the parent window (unless child+tooltip?).
+ - scrolling: while holding down a scrollbar, try to keep the same contents visible (at least while not moving mouse)
- scrolling: allow immediately effective change of scroll after Begin() if we haven't appended items yet.
- scrolling/clipping: separator on the initial position of a window is not visible (cursorpos.y <= clippos.y). (2017-08-20: can't repro)
- scrolling/style: shadows on scrollable areas to denote that there is more contents
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index a5f8f86..856531b 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -3375,10 +3375,15 @@
{
ImGuiTextBuffer Buf;
ImGuiTextFilter Filter;
- ImVector<int> LineOffsets; // Index to lines offset
+ ImVector<int> LineOffsets; // Index to lines offset. We maintain this with AddLog() calls, allowing us to have a random access on lines
bool ScrollToBottom;
- void Clear() { Buf.clear(); LineOffsets.clear(); }
+ void Clear()
+ {
+ Buf.clear();
+ LineOffsets.clear();
+ LineOffsets.push_back(0);
+ }
void AddLog(const char* fmt, ...) IM_FMTARGS(2)
{
@@ -3389,13 +3394,12 @@
va_end(args);
for (int new_size = Buf.size(); old_size < new_size; old_size++)
if (Buf[old_size] == '\n')
- LineOffsets.push_back(old_size);
+ LineOffsets.push_back(old_size + 1);
ScrollToBottom = true;
}
void Draw(const char* title, bool* p_open = NULL)
{
- ImGui::SetNextWindowSize(ImVec2(500,400), ImGuiCond_FirstUseEver);
if (!ImGui::Begin(title, p_open))
{
ImGui::End();
@@ -3408,24 +3412,47 @@
Filter.Draw("Filter", -100.0f);
ImGui::Separator();
ImGui::BeginChild("scrolling", ImVec2(0,0), false, ImGuiWindowFlags_HorizontalScrollbar);
- if (copy) ImGui::LogToClipboard();
+ if (copy)
+ ImGui::LogToClipboard();
+ ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(0, 0));
+ const char* buf = Buf.begin();
+ const char* buf_end = Buf.end();
if (Filter.IsActive())
{
- const char* buf_begin = Buf.begin();
- const char* line = buf_begin;
- for (int line_no = 0; line != NULL; line_no++)
+ for (int line_no = 0; line_no < LineOffsets.Size; line_no++)
{
- const char* line_end = (line_no < LineOffsets.Size) ? buf_begin + LineOffsets[line_no] : NULL;
- if (Filter.PassFilter(line, line_end))
- ImGui::TextUnformatted(line, line_end);
- line = line_end && line_end[1] ? line_end + 1 : NULL;
+ const char* line_start = buf + LineOffsets[line_no];
+ const char* line_end = (line_no + 1 < LineOffsets.Size) ? (buf + LineOffsets[line_no + 1] - 1) : buf_end;
+ if (Filter.PassFilter(line_start, line_end))
+ ImGui::TextUnformatted(line_start, line_end);
}
}
else
{
- ImGui::TextUnformatted(Buf.begin());
+ // The simplest and easy way to display the entire buffer:
+ // ImGui::TextUnformatted(buf_begin, buf_end);
+ // And it'll just work. TextUnformatted() has specialization for large blob of text and will fast-forward to skip non-visible lines.
+ // Here we instead demonstrate using the clipper to only process lines that are within the visible area.
+ // If you have tens of thousands of items and their processing cost is non-negligible, coarse clipping them on your side is recommended.
+ // Using ImGuiListClipper requires A) random access into your data, and B) items all being the same height,
+ // both of which we can handle since we an array pointing to the beginning of each line of text.
+ // When using the filter (in the block of code above) we don't have random access into the data to display anymore, which is why we don't use the clipper.
+ // Storing or skimming through the search result would make it possible (and would be recommended if you want to search through tens of thousands of entries)
+ ImGuiListClipper clipper;
+ clipper.Begin(LineOffsets.Size);
+ while (clipper.Step())
+ {
+ for (int line_no = clipper.DisplayStart; line_no < clipper.DisplayEnd; line_no++)
+ {
+ const char* line_start = buf + LineOffsets[line_no];
+ const char* line_end = (line_no + 1 < LineOffsets.Size) ? (buf + LineOffsets[line_no + 1] - 1) : buf_end;
+ ImGui::TextUnformatted(line_start, line_end);
+ }
+ }
+ clipper.End();
}
+ ImGui::PopStyleVar();
if (ScrollToBottom)
ImGui::SetScrollHereY(1.0f);
@@ -3440,15 +3467,23 @@
{
static ExampleAppLog log;
- // Demo: add random items (unless Ctrl is held)
- static double last_time = -1.0;
- double time = ImGui::GetTime();
- if (time - last_time >= 0.20f && !ImGui::GetIO().KeyCtrl)
+ // For the demo: add a debug button before the normal log window contents
+ // We take advantage of the fact that multiple calls to Begin()/End() are appending to the same window.
+ ImGui::SetNextWindowSize(ImVec2(500, 400), ImGuiCond_FirstUseEver);
+ ImGui::Begin("Example: Log", p_open);
+ if (ImGui::SmallButton("Add 5 entries"))
{
- const char* random_words[] = { "system", "info", "warning", "error", "fatal", "notice", "log" };
- log.AddLog("[%s] Hello, time is %.1f, frame count is %d\n", random_words[rand() % IM_ARRAYSIZE(random_words)], time, ImGui::GetFrameCount());
- last_time = time;
+ static int counter = 0;
+ for (int n = 0; n < 5; n++)
+ {
+ const char* categories[3] = { "info", "warn", "error" };
+ const char* words[] = { "Bumfuzzled", "Cattywampus", "Snickersnee", "Abibliophobia", "Absquatulate", "Nincompoop", "Pauciloquent" };
+ log.AddLog("[%05d] [%s] Hello, current time is %.1f, here's a word: '%s'\n",
+ ImGui::GetFrameCount(), categories[counter % IM_ARRAYSIZE(categories)], ImGui::GetTime(), words[counter % IM_ARRAYSIZE(words)]);
+ counter++;
+ }
}
+ ImGui::End();
log.Draw("Example: Log", p_open);
}
