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udpscope/src/help_window.cpp
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2026-10-05 00:28:10 +02:00

352 lines
16 KiB
C++

// SPDX-License-Identifier: MIT
#include "help_window.hpp"
#include <adwaita.h>
#include <cstdio>
#include <string>
#include "build_info.hpp"
#include "layout_store.hpp"
#include "shortcuts.hpp"
namespace udpscope {
namespace {
/// Nulled by each window's own close handler, so a second open cannot present a dead widget.
/// One pointer per window, file-scope because there is one application.
///
/// The help window is a `GtkWindow`. The other two are `AdwDialog`s, which are **not**
/// `GtkWindow`s: they have no `::close-request`, so they clear on `::closed` and close with
/// `adw_dialog_close()`.
GtkWidget* g_help = nullptr;
AdwDialog* g_about = nullptr;
AdwDialog* g_shortcuts = nullptr;
gboolean on_window_close(GtkWindow* window, gpointer slot) {
(void)window;
*static_cast<GtkWidget**>(slot) = nullptr;
return FALSE; // let the default handler destroy it
}
/// Shared by both `AdwDialog`s: the pointer to clear is the `user_data`, so there is one
/// handler rather than one per dialog.
void on_dialog_closed(AdwDialog* dialog, gpointer slot) {
(void)dialog;
*static_cast<AdwDialog**>(slot) = nullptr;
}
struct HelpPage {
const char* section; ///< the group heading in the sidebar
const char* title; ///< the row's label and the page's heading
const char* resource; ///< a path under /org/udpscope/help
/// The screenshots shown above the text, as resource paths and a null terminator. A page
/// with none is the common case and the reason this is a list rather than one field: the
/// overview carries two, the window and a held capture.
const char* const* images = nullptr;
};
/// Adding a page is one .txt file, one <file> line in the manifest and one row here.
/// The order here is the order the sidebar shows; `section` groups consecutive rows.
/// How tall a page's screenshots are drawn. They are scaled to fit this *height* and centre
/// themselves in it, so a 1500x950 capture is readable without a horizontal scrollbar.
constexpr int kHelpShotHeight = 260;
/// The screenshots each page carries, in the order it shows them.
constexpr const char* kOverviewShots[] = {"/org/udpscope/help/img/main-window.png",
"/org/udpscope/help/img/trigger-capture.png",
nullptr};
constexpr const char* kTriggerShots[] = {"/org/udpscope/help/img/trigger-capture.png",
nullptr};
constexpr const char* kMathShots[] = {"/org/udpscope/help/img/math-editor.png", nullptr};
constexpr HelpPage kPages[] = {
{"Getting started", "Overview", "/org/udpscope/help/01-overview.txt", kOverviewShots},
{"Getting started", "Choosing a source", "/org/udpscope/help/02-source.txt"},
{"Getting started", "Signals and calibration", "/org/udpscope/help/03-signals.txt"},
{"Getting started", "Rows, layout and drag & drop", "/org/udpscope/help/04-layout.txt"},
{"Viewing", "Time window", "/org/udpscope/help/05-window.txt"},
{"Viewing", "Navigating the plot", "/org/udpscope/help/06-navigate.txt"},
{"Viewing", "Pause and play", "/org/udpscope/help/07-pause.txt"},
{"Viewing", "Trigger", "/org/udpscope/help/08-trigger.txt", kTriggerShots},
{"Analysis", "Cursors", "/org/udpscope/help/09-cursors.txt"},
{"Analysis", "Measurements", "/org/udpscope/help/10-measurements.txt"},
{"Analysis", "Math channels", "/org/udpscope/help/11-math.txt", kMathShots},
{"Output and state", "Saving and export", "/org/udpscope/help/12-export.txt"},
{"Output and state", "Sessions and settings", "/org/udpscope/help/13-sessions.txt"},
{"Output and state", "Status bar and diagnostics", "/org/udpscope/help/14-status.txt"},
};
constexpr int kPageCount = static_cast<int>(sizeof(kPages) / sizeof(kPages[0]));
/// The page's markup, or a one-line stand-in. `ok` reports whether the real body loaded
/// *and* parsed: a missing resource and markup Pango rejects both render the stand-in,
/// because a help window that fails to open is worse than one page that says so.
std::string load_page(const HelpPage& page, bool* ok) {
*ok = false;
GError* error = nullptr;
GBytes* bytes = g_resources_lookup_data(page.resource, G_RESOURCE_LOOKUP_FLAGS_NONE,
&error);
if (bytes == nullptr) {
if (error != nullptr) g_error_free(error);
return "<i>This page is missing from the build.</i>";
}
gsize size = 0;
const char* data = static_cast<const char*>(g_bytes_get_data(bytes, &size));
std::string body(data, size);
g_bytes_unref(bytes);
if (!pango_parse_markup(body.c_str(), -1, 0, nullptr, nullptr, nullptr, &error)) {
if (error != nullptr) g_error_free(error);
return "<i>This page could not be displayed: its markup is malformed.</i>";
}
*ok = true;
return body;
}
void on_help_row_selected(GtkListBox*, GtkListBoxRow* row, gpointer body_label) {
if (row == nullptr) return;
const int idx = GPOINTER_TO_INT(g_object_get_data(G_OBJECT(row), "help-page"));
if (idx < 0 || idx >= kPageCount) return;
bool ok = false;
const std::string body = load_page(kPages[idx], &ok);
gtk_label_set_markup(GTK_LABEL(body_label), body.c_str());
// The screenshots above it, if this page has any. The column is the label's previous sibling
// inside the page's box, which is what lets this handler stay a matter of the label alone --
// and refilling it is a page *switch*, not a frame, so rebuilding it here is cheap and is
// also the only way to be sure the pictures are this page's and not the last one's.
GtkWidget* label = GTK_WIDGET(body_label);
GtkWidget* parent = gtk_widget_get_parent(label);
GtkWidget* shots = parent != nullptr ? gtk_widget_get_first_child(parent) : nullptr;
if (shots != nullptr && GTK_IS_BOX(shots)) {
while (GtkWidget* old = gtk_widget_get_first_child(shots)) {
gtk_box_remove(GTK_BOX(shots), old);
}
for (const char* const* img = kPages[idx].images; img != nullptr && *img != nullptr; ++img) {
GtkWidget* shot = gtk_picture_new_for_resource(*img);
gtk_picture_set_can_shrink(GTK_PICTURE(shot), TRUE);
// A height, and `CONTAIN` (the default) to fit the image inside it: a picture that may
// shrink asks for no height at all in a box, so without this it is allocated nothing and
// the page shows its text with a gap where the screenshots should be.
gtk_widget_set_size_request(shot, -1, kHelpShotHeight);
gtk_box_append(GTK_BOX(shots), shot);
}
gtk_widget_set_visible(shots, gtk_widget_get_first_child(shots) != nullptr);
}
}
} // namespace
void show_about(GtkWindow* parent, const std::string& session_path) {
if (g_about != nullptr) {
adw_dialog_present(g_about, GTK_WIDGET(parent));
return;
}
// `AdwAboutDialog` rather than `GtkAboutDialog`: it shows the application icon as the page's
// own header, which is the whole reason the app has one, and `adw_about_window_new()` is
// deprecated in favour of it. It is an `AdwDialog`, so it is modal on what it is presented
// on and needs no transient-for or modal call of its own.
AdwDialog* dialog = adw_about_dialog_new();
g_about = dialog;
AdwAboutDialog* about = ADW_ABOUT_DIALOG(dialog);
adw_about_dialog_set_application_name(about, "udpscope");
adw_about_dialog_set_application_icon(about, "org.udpscope.app");
adw_about_dialog_set_developer_name(about, "Martino Ferrari");
adw_about_dialog_set_version(about, build_info::kVersion);
adw_about_dialog_set_comments(about, "An oscilloscope for UDPStreamer sources.");
adw_about_dialog_set_license_type(about, GTK_LICENSE_MIT_X11);
adw_about_dialog_set_website(about, "https://git.ferrarinas.it/martino/udpscope");
// `debug_info` rather than `system_information`: it renders as a Troubleshooting page with a
// copy button, where the old field was inert text a user had to retype. A `std::string`
// rather than a fixed buffer, because a long settings path used to truncate it silently.
const std::string debug = "Commit: " + std::string(build_info::kCommit) +
"\nBuilt: " + build_info::kTimestamp +
"\nSettings: " + config_dir() +
"\nSession file: " + session_path;
adw_about_dialog_set_debug_info(about, debug.c_str());
g_signal_connect(dialog, "closed", G_CALLBACK(on_dialog_closed), &g_about);
adw_dialog_present(dialog, GTK_WIDGET(parent));
}
const char* about_icon_name() {
if (g_about == nullptr) return "";
return adw_about_dialog_get_application_icon(ADW_ABOUT_DIALOG(g_about));
}
HelpReport help_self_check() {
HelpReport report;
report.pages = kPageCount;
for (const HelpPage& page : kPages) {
bool ok = false;
const std::string body = load_page(page, &ok);
if (ok && !body.empty()) ++report.parsed;
if (report.shortest_title.empty() || body.size() < report.shortest_bytes) {
report.shortest_title = page.title;
report.shortest_bytes = body.size();
}
}
return report;
}
void show_help(GtkWindow* parent) {
if (g_help != nullptr) {
gtk_window_present(GTK_WINDOW(g_help));
return;
}
GtkWidget* window = gtk_window_new();
g_help = window;
gtk_window_set_title(GTK_WINDOW(window), "udpscope help");
gtk_window_set_default_size(GTK_WINDOW(window), 860, 640);
gtk_window_set_transient_for(GTK_WINDOW(window), parent);
// One label, width-locked by the scrolled window, holding one page's markup. The
// sidebar swaps the markup rather than rebuilding anything.
GtkWidget* body = gtk_label_new(nullptr);
gtk_label_set_use_markup(GTK_LABEL(body), TRUE);
gtk_label_set_wrap(GTK_LABEL(body), TRUE);
gtk_label_set_xalign(GTK_LABEL(body), 0.0f);
gtk_label_set_yalign(GTK_LABEL(body), 0.0f);
gtk_label_set_selectable(GTK_LABEL(body), TRUE);
gtk_widget_set_margin_start(body, 18);
gtk_widget_set_margin_end(body, 18);
gtk_widget_set_margin_top(body, 14);
gtk_widget_set_margin_bottom(body, 14);
GtkWidget* body_scroll = gtk_scrolled_window_new();
gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(body_scroll), GTK_POLICY_NEVER,
GTK_POLICY_AUTOMATIC);
// The page's own column: its screenshots above its text. Built once and *refilled* by the page
// switch, which is why no picture is made here -- one `GtkPicture` per image of the page.
GtkWidget* shot_box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 8);
gtk_widget_set_margin_start(shot_box, 18);
gtk_widget_set_margin_end(shot_box, 18);
gtk_widget_set_margin_top(shot_box, 14);
gtk_widget_set_visible(shot_box, false);
GtkWidget* page_box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 0);
gtk_box_append(GTK_BOX(page_box), shot_box);
gtk_box_append(GTK_BOX(page_box), body);
gtk_scrolled_window_set_child(GTK_SCROLLED_WINDOW(body_scroll), page_box);
gtk_widget_set_hexpand(body_scroll, TRUE);
GtkWidget* list = gtk_list_box_new();
gtk_list_box_set_selection_mode(GTK_LIST_BOX(list), GTK_SELECTION_SINGLE);
const char* current_section = nullptr;
for (int i = 0; i < kPageCount; ++i) {
if (current_section == nullptr ||
std::string(current_section) != kPages[i].section) {
current_section = kPages[i].section;
GtkWidget* heading = gtk_label_new(nullptr);
char markup[128];
std::snprintf(markup, sizeof(markup), "<b><small>%s</small></b>", current_section);
gtk_label_set_markup(GTK_LABEL(heading), markup);
gtk_label_set_xalign(GTK_LABEL(heading), 0.0f);
gtk_widget_set_margin_start(heading, 10);
gtk_widget_set_margin_top(heading, 10);
gtk_widget_set_margin_bottom(heading, 2);
GtkWidget* heading_row = gtk_list_box_row_new();
gtk_list_box_row_set_selectable(GTK_LIST_BOX_ROW(heading_row), FALSE);
gtk_list_box_row_set_activatable(GTK_LIST_BOX_ROW(heading_row), FALSE);
gtk_list_box_row_set_child(GTK_LIST_BOX_ROW(heading_row), heading);
gtk_list_box_append(GTK_LIST_BOX(list), heading_row);
}
GtkWidget* label = gtk_label_new(kPages[i].title);
gtk_label_set_xalign(GTK_LABEL(label), 0.0f);
gtk_widget_set_margin_start(label, 18);
gtk_widget_set_margin_end(label, 10);
gtk_widget_set_margin_top(label, 4);
gtk_widget_set_margin_bottom(label, 4);
GtkWidget* row = gtk_list_box_row_new();
gtk_list_box_row_set_child(GTK_LIST_BOX_ROW(row), label);
g_object_set_data(G_OBJECT(row), "help-page", GINT_TO_POINTER(i));
gtk_list_box_append(GTK_LIST_BOX(list), row);
}
g_signal_connect(list, "row-selected", G_CALLBACK(on_help_row_selected), body);
GtkWidget* list_scroll = gtk_scrolled_window_new();
gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(list_scroll), GTK_POLICY_NEVER,
GTK_POLICY_AUTOMATIC);
gtk_scrolled_window_set_child(GTK_SCROLLED_WINDOW(list_scroll), list);
gtk_widget_set_size_request(list_scroll, 220, -1);
GtkWidget* split = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
gtk_box_append(GTK_BOX(split), list_scroll);
gtk_box_append(GTK_BOX(split), gtk_separator_new(GTK_ORIENTATION_VERTICAL));
gtk_box_append(GTK_BOX(split), body_scroll);
gtk_window_set_child(GTK_WINDOW(window), split);
// Select the first page so the window never opens blank.
GtkListBoxRow* first = gtk_list_box_get_row_at_index(GTK_LIST_BOX(list), 1);
if (first != nullptr) gtk_list_box_select_row(GTK_LIST_BOX(list), first);
g_signal_connect(window, "close-request", G_CALLBACK(on_window_close), &g_help);
gtk_window_present(GTK_WINDOW(window));
}
namespace {
/// Appends one table row to `dialog`, opening a new section whenever the row's `section`
/// string differs from the last one. `*current` is the section being filled, `*title` the
/// name it carries; both are owned by the caller so the two tables share one run.
///
/// `accel` is handed to `AdwShortcutsItem` as an accelerator when it is non-empty and
/// `subtitle` is used when it is not, which is how a wheel or a drag gets a row: neither
/// GTK's nor libadwaita's accelerator syntax can name one, and asking them to parse
/// "Wheel" costs a parse warning and draws nothing.
void append_shortcut(AdwShortcutsDialog* dialog, AdwShortcutsSection** current,
const char** title, const char* section, const char* accel,
const char* subtitle, const char* description) {
if (*current == nullptr || std::string(*title) != section) {
*current = adw_shortcuts_section_new(section);
*title = section;
adw_shortcuts_dialog_add(dialog, *current);
}
AdwShortcutsItem* item = adw_shortcuts_item_new(description, accel);
if (subtitle != nullptr && *subtitle != '\0') {
adw_shortcuts_item_set_subtitle(item, subtitle);
}
adw_shortcuts_section_add(*current, item);
}
} // namespace
void show_shortcuts(GtkWindow* parent) {
if (g_shortcuts != nullptr) {
adw_dialog_present(g_shortcuts, GTK_WIDGET(parent));
return;
}
AdwDialog* dialog = adw_shortcuts_dialog_new();
g_shortcuts = dialog;
adw_dialog_set_title(dialog, "Keyboard and mouse shortcuts");
AdwShortcutsSection* section = nullptr;
const char* section_title = nullptr;
int accel_count = 0;
const Accel* accels = app_accels(&accel_count);
for (int i = 0; i < accel_count; ++i) {
append_shortcut(ADW_SHORTCUTS_DIALOG(dialog), &section, &section_title,
accels[i].section, accels[i].accel, "", accels[i].description);
}
int gesture_count = 0;
const Gesture* gestures = plot_gestures(&gesture_count);
for (int i = 0; i < gesture_count; ++i) {
append_shortcut(ADW_SHORTCUTS_DIALOG(dialog), &section, &section_title,
gestures[i].section, gestures[i].accel, gestures[i].subtitle,
gestures[i].description);
}
g_signal_connect(dialog, "closed", G_CALLBACK(on_dialog_closed), &g_shortcuts);
adw_dialog_present(dialog, GTK_WIDGET(parent));
}
void close_help_windows() {
if (g_help != nullptr) gtk_window_close(GTK_WINDOW(g_help));
if (g_about != nullptr) adw_dialog_close(g_about);
if (g_shortcuts != nullptr) adw_dialog_close(g_shortcuts);
}
} // namespace udpscope