DPF

DISTRHO Plugin Framework
Log | Files | Refs | Submodules | README | LICENSE

gui.h (9010B)


      1 #pragma once
      2 
      3 #include "../plugin.h"
      4 
      5 /// @page GUI
      6 ///
      7 /// This extension defines how the plugin will present its GUI.
      8 ///
      9 /// There are two approaches:
     10 /// 1. the plugin creates a window and embeds it into the host's window
     11 /// 2. the plugin creates a floating window
     12 ///
     13 /// Embedding the window gives more control to the host, and feels more integrated.
     14 /// Floating window are sometimes the only option due to technical limitations.
     15 ///
     16 /// Showing the GUI works as follow:
     17 ///  1. clap_plugin_gui->is_api_supported(), check what can work
     18 ///  2. clap_plugin_gui->create(), allocates gui resources
     19 ///  3. if the plugin window is floating
     20 ///  4.    -> clap_plugin_gui->set_transient()
     21 ///  5.    -> clap_plugin_gui->suggest_title()
     22 ///  6. else
     23 ///  7.    -> clap_plugin_gui->set_scale()
     24 ///  8.    -> clap_plugin_gui->can_resize()
     25 ///  9.    -> if resizable and has known size from previous session, clap_plugin_gui->set_size()
     26 /// 10.    -> else clap_plugin_gui->get_size(), gets initial size
     27 /// 11.    -> clap_plugin_gui->set_parent()
     28 /// 12. clap_plugin_gui->show()
     29 /// 13. clap_plugin_gui->hide()/show() ...
     30 /// 14. clap_plugin_gui->destroy() when done with the gui
     31 ///
     32 /// Resizing the window (initiated by the plugin, if embedded):
     33 /// 1. Plugins calls clap_host_gui->request_resize()
     34 /// 2. If the host returns true the new size is accepted,
     35 ///    the host doesn't have to call clap_plugin_gui->set_size().
     36 ///    If the host returns false, the new size is rejected.
     37 ///
     38 /// Resizing the window (drag, if embedded)):
     39 /// 1. Only possible if clap_plugin_gui->can_resize() returns true
     40 /// 2. Mouse drag -> new_size
     41 /// 3. clap_plugin_gui->adjust_size(new_size) -> working_size
     42 /// 4. clap_plugin_gui->set_size(working_size)
     43 
     44 static CLAP_CONSTEXPR const char CLAP_EXT_GUI[] = "clap.gui";
     45 
     46 // If your windowing API is not listed here, please open an issue and we'll figure it out.
     47 // https://github.com/free-audio/clap/issues/new
     48 
     49 // uses physical size
     50 // embed using https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setparent
     51 static const CLAP_CONSTEXPR char CLAP_WINDOW_API_WIN32[] = "win32";
     52 
     53 // uses logical size, don't call clap_plugin_gui->set_scale()
     54 static const CLAP_CONSTEXPR char CLAP_WINDOW_API_COCOA[] = "cocoa";
     55 
     56 // uses physical size
     57 // embed using https://specifications.freedesktop.org/xembed-spec/xembed-spec-latest.html
     58 static const CLAP_CONSTEXPR char CLAP_WINDOW_API_X11[] = "x11";
     59 
     60 // uses physical size
     61 // embed is currently not supported, use floating windows
     62 static const CLAP_CONSTEXPR char CLAP_WINDOW_API_WAYLAND[] = "wayland";
     63 
     64 #ifdef __cplusplus
     65 extern "C" {
     66 #endif
     67 
     68 typedef void         *clap_hwnd;
     69 typedef void         *clap_nsview;
     70 typedef unsigned long clap_xwnd;
     71 
     72 // Represent a window reference.
     73 typedef struct clap_window {
     74    const char *api; // one of CLAP_WINDOW_API_XXX
     75    union {
     76       clap_nsview cocoa;
     77       clap_xwnd   x11;
     78       clap_hwnd   win32;
     79       void       *ptr; // for anything defined outside of clap
     80       uintptr_t   uptr;
     81    };
     82 } clap_window_t;
     83 
     84 // Information to improve window resizing when initiated by the host or window manager.
     85 typedef struct clap_gui_resize_hints {
     86    bool can_resize_horizontally;
     87    bool can_resize_vertically;
     88 
     89    // only if can resize horizontally and vertically
     90    bool     preserve_aspect_ratio;
     91    uint32_t aspect_ratio_width;
     92    uint32_t aspect_ratio_height;
     93 } clap_gui_resize_hints_t;
     94 
     95 // Size (width, height) is in pixels; the corresponding windowing system extension is
     96 // responsible for defining if it is physical pixels or logical pixels.
     97 typedef struct clap_plugin_gui {
     98    // Returns true if the requested gui api is supported
     99    // [main-thread]
    100    bool(CLAP_ABI *is_api_supported)(const clap_plugin_t *plugin, const char *api, bool is_floating);
    101 
    102    // Returns true if the plugin has a preferred api.
    103    // The host has no obligation to honor the plugin preferrence, this is just a hint.
    104    // The const char **api variable should be explicitly assigned as a pointer to
    105    // one of the CLAP_WINDOW_API_ constants defined above, not strcopied.
    106    // [main-thread]
    107    bool(CLAP_ABI *get_preferred_api)(const clap_plugin_t *plugin,
    108                                      const char         **api,
    109                                      bool                *is_floating);
    110 
    111    // Create and allocate all resources necessary for the gui.
    112    //
    113    // If is_floating is true, then the window will not be managed by the host. The plugin
    114    // can set its window to stays above the parent window, see set_transient().
    115    // api may be null or blank for floating window.
    116    //
    117    // If is_floating is false, then the plugin has to embbed its window into the parent window, see
    118    // set_parent().
    119    //
    120    // After this call, the GUI may not be visible yet; don't forget to call show().
    121    // [main-thread]
    122    bool(CLAP_ABI *create)(const clap_plugin_t *plugin, const char *api, bool is_floating);
    123 
    124    // Free all resources associated with the gui.
    125    // [main-thread]
    126    void(CLAP_ABI *destroy)(const clap_plugin_t *plugin);
    127 
    128    // Set the absolute GUI scaling factor, and override any OS info.
    129    // Should not be used if the windowing api relies upon logical pixels.
    130    //
    131    // If the plugin prefers to work out the scaling factor itself by querying the OS directly,
    132    // then ignore the call.
    133    //
    134    // Returns true if the scaling could be applied
    135    // Returns false if the call was ignored, or the scaling could not be applied.
    136    // [main-thread]
    137    bool(CLAP_ABI *set_scale)(const clap_plugin_t *plugin, double scale);
    138 
    139    // Get the current size of the plugin UI.
    140    // clap_plugin_gui->create() must have been called prior to asking the size.
    141    // [main-thread]
    142    bool(CLAP_ABI *get_size)(const clap_plugin_t *plugin, uint32_t *width, uint32_t *height);
    143 
    144    // Returns true if the window is resizeable (mouse drag).
    145    // Only for embedded windows.
    146    // [main-thread]
    147    bool(CLAP_ABI *can_resize)(const clap_plugin_t *plugin);
    148 
    149    // Returns true if the plugin can provide hints on how to resize the window.
    150    // [main-thread]
    151    bool(CLAP_ABI *get_resize_hints)(const clap_plugin_t *plugin, clap_gui_resize_hints_t *hints);
    152 
    153    // If the plugin gui is resizable, then the plugin will calculate the closest
    154    // usable size which fits in the given size.
    155    // This method does not change the size.
    156    //
    157    // Only for embedded windows.
    158    // [main-thread]
    159    bool(CLAP_ABI *adjust_size)(const clap_plugin_t *plugin, uint32_t *width, uint32_t *height);
    160 
    161    // Sets the window size. Only for embedded windows.
    162    // [main-thread]
    163    bool(CLAP_ABI *set_size)(const clap_plugin_t *plugin, uint32_t width, uint32_t height);
    164 
    165    // Embbeds the plugin window into the given window.
    166    // [main-thread & !floating]
    167    bool(CLAP_ABI *set_parent)(const clap_plugin_t *plugin, const clap_window_t *window);
    168 
    169    // Set the plugin floating window to stay above the given window.
    170    // [main-thread & floating]
    171    bool(CLAP_ABI *set_transient)(const clap_plugin_t *plugin, const clap_window_t *window);
    172 
    173    // Suggests a window title. Only for floating windows.
    174    // [main-thread & floating]
    175    void(CLAP_ABI *suggest_title)(const clap_plugin_t *plugin, const char *title);
    176 
    177    // Show the window.
    178    // [main-thread]
    179    bool(CLAP_ABI *show)(const clap_plugin_t *plugin);
    180 
    181    // Hide the window, this method does not free the resources, it just hides
    182    // the window content. Yet it may be a good idea to stop painting timers.
    183    // [main-thread]
    184    bool(CLAP_ABI *hide)(const clap_plugin_t *plugin);
    185 } clap_plugin_gui_t;
    186 
    187 typedef struct clap_host_gui {
    188    // The host should call get_resize_hints() again.
    189    // [thread-safe]
    190    void(CLAP_ABI *resize_hints_changed)(const clap_host_t *host);
    191 
    192    /* Request the host to resize the client area to width, height.
    193     * Return true if the new size is accepted, false otherwise.
    194     * The host doesn't have to call set_size().
    195     *
    196     * Note: if not called from the main thread, then a return value simply means that the host
    197     * acknowledged the request and will process it asynchronously. If the request then can't be
    198     * satisfied then the host will call set_size() to revert the operation.
    199     *
    200     * [thread-safe] */
    201    bool(CLAP_ABI *request_resize)(const clap_host_t *host, uint32_t width, uint32_t height);
    202 
    203    /* Request the host to show the plugin gui.
    204     * Return true on success, false otherwise.
    205     * [thread-safe] */
    206    bool(CLAP_ABI *request_show)(const clap_host_t *host);
    207 
    208    /* Request the host to hide the plugin gui.
    209     * Return true on success, false otherwise.
    210     * [thread-safe] */
    211    bool(CLAP_ABI *request_hide)(const clap_host_t *host);
    212 
    213    // The floating window has been closed, or the connection to the gui has been lost.
    214    //
    215    // If was_destroyed is true, then the host must call clap_plugin_gui->destroy() to acknowledge
    216    // the gui destruction.
    217    // [thread-safe]
    218    void(CLAP_ABI *closed)(const clap_host_t *host, bool was_destroyed);
    219 } clap_host_gui_t;
    220 
    221 #ifdef __cplusplus
    222 }
    223 #endif