echomap::FilesystemCombo Class Reference

Provides a platform-independent Dear ImGui combo box for browsing the file-system and selecting files. More...

#include <FilesystemCombo.hpp>

Classes
struct	Entry
	A drawable and selectable representation of a file or directory on the file-system. More...
struct	BrowseTarget
	A root target selected by the user to focus on. More...
struct	EntryCache
	A cache of Entry objects under a single root directory. More...

Public Member Functions
	FilesystemCombo (EchoMap *app)
	Sets up a new FilesystemCombo with the given EchoMap application context.
bool	operator() (std::filesystem::path &selected_path)
	Draws the FilesystemCombo control.

Private Member Functions
void	invalidate_cache ()
	Invalidates the EntryCache.
void	update_current_state (const std::filesystem::path &path)
	Copies and formats the given path into the fixed-size current directory state member variable.
bool	draw_combo_body (std::filesystem::path &selected_path)
BrowseTarget	get_browse_target () const
bool	draw_parent_entry (const std::filesystem::path &directory)
bool	draw_child_entries (std::string_view filter, std::filesystem::path &selected_path)
void	accept_path (std::filesystem::path &selected_path, const std::filesystem::path &path)

Private Attributes
std::array< char, max_path_length >	current_root {}
	The current raw string entered by the user.
BrowseTarget	current_target
	The current target specified in the filter window.
std::optional< EntryCache >	cache
	Cache of entries visible in the combo box.
EchoMap *	app
	Pointer to the owning application instance.

Static Private Attributes
static constexpr unsigned int	max_path_length = 4096
	Maximum number of characters in a filesystem path.

Detailed Description

Provides a platform-independent Dear ImGui combo box for browsing the file-system and selecting files.

Definition at line 31 of file FilesystemCombo.hpp.

Constructor & Destructor Documentation

FilesystemCombo()

echomap::FilesystemCombo::FilesystemCombo ( EchoMap * app )

explicit

Sets up a new FilesystemCombo with the given EchoMap application context.

The initial location is the current working directory.

Parameters

app	The owning application instance.

Exceptions

std::runtime_error

The CWD could not be interrogated.

Definition at line 24 of file FilesystemCombo.cpp.

  :
    app(app)
{
    std::error_code error_code;
    const auto cwd = std::filesystem::current_path(error_code);
 
    if (error_code || cwd.empty() || !std::filesystem::is_directory(cwd))
        throw std::runtime_error("Could not get the current working directory. Is the filesystem readable?");
 
    update_current_state(cwd);
}

Member Function Documentation

accept_path()

void echomap::FilesystemCombo::accept_path ( std::filesystem::path & selected_path, const std::filesystem::path & path )

private

Definition at line 266 of file FilesystemCombo.cpp.

{
    if (std::filesystem::is_directory(path)) {
        update_current_state(path);
        return;
    }
 
    selected_path = path;
 
    if (path.has_parent_path())
        update_current_state(path.parent_path());
    else
        update_current_state(".");
}

draw_child_entries()

bool echomap::FilesystemCombo::draw_child_entries ( std::string_view filter, std::filesystem::path & selected_path )

private

Definition at line 227 of file FilesystemCombo.cpp.

{
    assert(cache.has_value());
 
    bool has_visible_entries = false;
    bool changed = false;
 
    for (const auto& entry : cache->entries) {
        if (!filter.empty() && !entry.name.contains(filter))
            continue;
 
        has_visible_entries = true;
 
        if (!entry.draw())
            continue;
 
        if (entry.is_directory) {
            update_current_state(entry.path);
            return false;
        }
 
        selected_path = entry.path;
        update_current_state(entry.path.parent_path());
 
        changed = true;
        ImGui::CloseCurrentPopup();
 
        return changed;
    }
 
    if (!has_visible_entries)
        ImGui::TextDisabled("No matching entries.");
 
    return changed;
}

draw_combo_body()

bool echomap::FilesystemCombo::draw_combo_body ( std::filesystem::path & selected_path )

private

Definition at line 136 of file FilesystemCombo.cpp.

{
    ImGui::SetNextItemWidth(-std::numeric_limits<float>::min());
    const std::string old_root = current_root.data();
    const bool enter_pressed =
            ImGui::InputText("##path", current_root.data(), current_root.size(), ImGuiInputTextFlags_EnterReturnsTrue);
 
    bool changed = false;
 
    if (old_root != current_root.data())
        // If the browse target has changed, update the cached member variable.
        current_target = get_browse_target();
 
    if (enter_pressed) {
        // If the user has explicitly pressed 'enter', accept whatever is selected at this time.
        accept_path(
                selected_path,
                current_target.target_path.empty() ? current_target.parent_directory : current_target.target_path
        );
 
        changed = true;
        ImGui::CloseCurrentPopup();
    }
 
    ImGui::Separator();
 
    if (!std::filesystem::is_directory(current_target.parent_directory))
        ImGui::TextDisabled("Not a readable directory.");
    else {
        changed |= draw_parent_entry(current_target.parent_directory);
        if (!cache || cache->directory != current_target.parent_directory)
            cache.emplace(current_target.parent_directory);
 
        changed |= draw_child_entries(current_target.filter, selected_path);
    }
 
    return changed;
}

draw_parent_entry()

bool echomap::FilesystemCombo::draw_parent_entry ( const std::filesystem::path & directory )

private

Definition at line 210 of file FilesystemCombo.cpp.

{
    const std::filesystem::path parent = directory.parent_path();
 
    if (parent.empty() || parent == directory)
        return false;
 
    if (ImGui::Selectable("../", false, ImGuiSelectableFlags_NoAutoClosePopups)) {
        update_current_state(parent);
        return true;
    }
 
    return false;
}

get_browse_target()

FilesystemCombo::BrowseTarget echomap::FilesystemCombo::get_browse_target ( ) const

nodiscardprivate

Definition at line 177 of file FilesystemCombo.cpp.

{
    std::error_code error_code;
    const std::string typed_string = current_root.data();
    auto const typed_path = typed_string.empty() ? std::filesystem::path{} : std::filesystem::path{typed_string};
    auto lookup_path = typed_path;
 
    if (lookup_path.empty())
        lookup_path = std::filesystem::current_path(error_code);
    else if (lookup_path.is_relative())
        lookup_path = std::filesystem::absolute(lookup_path, error_code);
 
    if (error_code || lookup_path.empty())
        lookup_path = ".";
 
    error_code.clear();
 
    if (std::filesystem::is_directory(lookup_path, error_code))
        return {.target_path = lookup_path, .parent_directory = lookup_path, .filter = {}};
 
    std::filesystem::path directory = lookup_path.parent_path();
 
    if (directory.empty()) {
        error_code.clear();
        directory = std::filesystem::current_path(error_code);
 
        if (error_code || directory.empty())
            directory = ".";
    }
 
    return {.target_path = lookup_path, .parent_directory = directory, .filter = lookup_path.filename().string()};
}

invalidate_cache()

void echomap::FilesystemCombo::invalidate_cache ( )

private

Invalidates the EntryCache.

Definition at line 81 of file FilesystemCombo.cpp.

{
    cache.reset();
}

operator()()

bool echomap::FilesystemCombo::operator()

(

std::filesystem::path &

selected_path

)

Draws the FilesystemCombo control.

Parameters

selected_path

Output parameter for the selected file.

Returns

Has a new file been selected?

Precondition

A Dear ImGui panel's draw cycle must already be underway.

Definition at line 38 of file FilesystemCombo.cpp.

{
    bool changed = false;
 
    ImGui::SetNextItemWidth(-std::numeric_limits<float>::min());
 
    const std::string preview = selected_path.empty() ? std::string{current_root.data()} : selected_path.string();
 
    if (ImGui::BeginCombo("##FilesystemCombo", preview.c_str(), ImGuiComboFlags_HeightLarge)) {
        if (ImGui::IsWindowAppearing()) {
            ImGui::SetKeyboardFocusHere();
            invalidate_cache();
        }
 
        changed = draw_combo_body(selected_path);
 
        ImGui::EndCombo();
        app->increment_forced_frames();
    }
 
    return changed;
}

update_current_state()

void echomap::FilesystemCombo::update_current_state ( const std::filesystem::path & path )

private

Copies and formats the given path into the fixed-size current directory state member variable.

The current directory array is always NULL-terminated following this operation. The current BrowseTarget is also updated to the given path.

Parameters

path	The path to the new root directory.

Definition at line 123 of file FilesystemCombo.cpp.

{
    const std::string path_string = path.string();
    const std::size_t length = std::min(current_root.size() - 1, path_string.size());
 
    std::memcpy(current_root.data(), path_string.data(), length);
    current_root[length] = '\0';
 
    current_target = get_browse_target();
}

Member Data Documentation

app

EchoMap* echomap::FilesystemCombo::app

private

Pointer to the owning application instance.

Definition at line 186 of file FilesystemCombo.hpp.

cache

std::optional<EntryCache> echomap::FilesystemCombo::cache

private

Cache of entries visible in the combo box.

Definition at line 185 of file FilesystemCombo.hpp.

current_root

std::array<char, max_path_length> echomap::FilesystemCombo::current_root {}

private

The current raw string entered by the user.

Definition at line 183 of file FilesystemCombo.hpp.

{}; 

current_target

BrowseTarget echomap::FilesystemCombo::current_target

private

The current target specified in the filter window.

Definition at line 184 of file FilesystemCombo.hpp.

max_path_length

unsigned int echomap::FilesystemCombo::max_path_length = 4096

staticconstexprprivate

Maximum number of characters in a filesystem path.

Definition at line 55 of file FilesystemCombo.hpp.

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The documentation for this class was generated from the following files:

• src/panels/native/FilesystemCombo.hpp
• src/panels/native/FilesystemCombo.cpp