gui.h

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#pragma once
 
#include "../plugin.h"

 
static CLAP_CONSTEXPR const char CLAP_EXT_GUI[] = "clap.gui";
 
// If your windowing API is not listed here, please open an issue and we'll figure it out.
// https://github.com/free-audio/clap/issues/new
 
// uses physical size
// embed using https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setparent
static const CLAP_CONSTEXPR char CLAP_WINDOW_API_WIN32[] = "win32";
 
// uses logical size, don't call clap_plugin_gui->set_scale()
static const CLAP_CONSTEXPR char CLAP_WINDOW_API_COCOA[] = "cocoa";
 
// uses physical size
// embed using https://specifications.freedesktop.org/xembed-spec/xembed-spec-latest.html
static const CLAP_CONSTEXPR char CLAP_WINDOW_API_X11[] = "x11";
 
// uses physical size
// embed is currently not supported, use floating windows
static const CLAP_CONSTEXPR char CLAP_WINDOW_API_WAYLAND[] = "wayland";
 
#ifdef __cplusplus
extern "C" {
#endif
 
typedef void         *clap_hwnd;
typedef void         *clap_nsview;
typedef unsigned long clap_xwnd;
 
// Represent a window reference.
typedef struct clap_window {
   const char *api; // one of CLAP_WINDOW_API_XXX
   union {
      clap_nsview cocoa;
      clap_xwnd   x11;
      clap_hwnd   win32;
      void       *ptr; // for anything defined outside of clap
      uintptr_t   uptr;
   };
} clap_window_t;
 
// Information to improve window resizing when initiated by the host or window manager.
typedef struct clap_gui_resize_hints {
   bool can_resize_horizontally;
   bool can_resize_vertically;
 
   // only if can resize horizontally and vertically
   bool     preserve_aspect_ratio;
   uint32_t aspect_ratio_width;
   uint32_t aspect_ratio_height;
} clap_gui_resize_hints_t;
 
// Size (width, height) is in pixels; the corresponding windowing system extension is
// responsible for defining if it is physical pixels or logical pixels.
typedef struct clap_plugin_gui {
   // Returns true if the requested gui api is supported
   // [main-thread]
   bool (CLAP_ABI *is_api_supported)(const clap_plugin_t *plugin, const char *api, bool is_floating);
 
   // Returns true if the plugin has a preferred api.
   // The host has no obligation to honor the plugin preferrence, this is just a hint.
   // [main-thread]
   bool (CLAP_ABI *get_preferred_api)(const clap_plugin_t *plugin, const char **api, bool *is_floating);
 
   // Create and allocate all resources necessary for the gui.
   //
   // If is_floating is true, then the window will not be managed by the host. The plugin
   // can set its window to stays above the parent window, see set_transient().
   // api may be null or blank for floating window.
   //
   // If is_floating is false, then the plugin has to embbed its window into the parent window, see
   // set_parent().
   //
   // After this call, the GUI may not be visible yet; don't forget to call show().
   // [main-thread]
   bool (CLAP_ABI *create)(const clap_plugin_t *plugin, const char *api, bool is_floating);
 
   // Free all resources associated with the gui.
   // [main-thread]
   void (CLAP_ABI *destroy)(const clap_plugin_t *plugin);
 
   // Set the absolute GUI scaling factor, and override any OS info.
   // Should not be used if the windowing api relies upon logical pixels.
   //
   // If the plugin prefers to work out the scaling factor itself by querying the OS directly,
   // then ignore the call.
   //
   // Returns true if the scaling could be applied
   // Returns false if the call was ignored, or the scaling could not be applied.
   // [main-thread]
   bool (CLAP_ABI *set_scale)(const clap_plugin_t *plugin, double scale);
 
   // Get the current size of the plugin UI.
   // clap_plugin_gui->create() must have been called prior to asking the size.
   // [main-thread]
   bool (CLAP_ABI *get_size)(const clap_plugin_t *plugin, uint32_t *width, uint32_t *height);
 
   // Returns true if the window is resizeable (mouse drag).
   // Only for embedded windows.
   // [main-thread]
   bool (CLAP_ABI *can_resize)(const clap_plugin_t *plugin);
 
   // Returns true if the plugin can provide hints on how to resize the window.
   // [main-thread]
   bool (CLAP_ABI *get_resize_hints)(const clap_plugin_t *plugin, clap_gui_resize_hints_t *hints);
 
   // If the plugin gui is resizable, then the plugin will calculate the closest
   // usable size which fits in the given size.
   // This method does not change the size.
   //
   // Only for embedded windows.
   // [main-thread]
   bool (CLAP_ABI *adjust_size)(const clap_plugin_t *plugin, uint32_t *width, uint32_t *height);
 
   // Sets the window size. Only for embedded windows.
   // [main-thread]
   bool (CLAP_ABI *set_size)(const clap_plugin_t *plugin, uint32_t width, uint32_t height);
 
   // Embbeds the plugin window into the given window.
   // [main-thread & !floating]
   bool (CLAP_ABI *set_parent)(const clap_plugin_t *plugin, const clap_window_t *window);
 
   // Set the plugin floating window to stay above the given window.
   // [main-thread & floating]
   bool (CLAP_ABI *set_transient)(const clap_plugin_t *plugin, const clap_window_t *window);
 
   // Suggests a window title. Only for floating windows.
   // [main-thread & floating]
   void (CLAP_ABI *suggest_title)(const clap_plugin_t *plugin, const char *title);
 
   // Show the window.
   // [main-thread]
   bool (CLAP_ABI *show)(const clap_plugin_t *plugin);
 
   // Hide the window, this method does not free the resources, it just hides
   // the window content. Yet it may be a good idea to stop painting timers.
   // [main-thread]
   bool (CLAP_ABI *hide)(const clap_plugin_t *plugin);
} clap_plugin_gui_t;
 
typedef struct clap_host_gui {
   // The host should call get_resize_hints() again.
   // [thread-safe]
   void (CLAP_ABI *resize_hints_changed)(const clap_host_t *host);
 
   /* Request the host to resize the client area to width, height.
    * Return true if the new size is accepted, false otherwise.
    * The host doesn't have to call set_size().
    *
    * Note: if not called from the main thread, then a return value simply means that the host
    * acknowledged the request and will process it asynchronously. If the request then can't be
    * satisfied then the host will call set_size() to revert the operation.
    *
    * [thread-safe] */
   bool (CLAP_ABI *request_resize)(const clap_host_t *host, uint32_t width, uint32_t height);
 
   /* Request the host to show the plugin gui.
    * Return true on success, false otherwise.
    * [thread-safe] */
   bool (CLAP_ABI *request_show)(const clap_host_t *host);
 
   /* Request the host to hide the plugin gui.
    * Return true on success, false otherwise.
    * [thread-safe] */
   bool (CLAP_ABI *request_hide)(const clap_host_t *host);
 
   // The floating window has been closed, or the connection to the gui has been lost.
   //
   // If was_destroyed is true, then the host must call clap_plugin_gui->destroy() to acknowledge
   // the gui destruction.
   // [thread-safe]
   void (CLAP_ABI *closed)(const clap_host_t *host, bool was_destroyed);
} clap_host_gui_t;
 
#ifdef __cplusplus
}
#endif