Panel.c

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/*
 * ObjectivelyMVC: Object oriented MVC framework for SDL3 and C.
 * Copyright (C) 2014 Jay Dolan <jay@jaydolan.com>
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source distribution.
 */
 
#include <assert.h>
 
#include "Panel.h"
 
#include "../Assets/resize.png.h"
 
static Image *_resize;
 
#define _Class _Panel
 
#pragma mark - Object
 
static void dealloc(Object *self) {
 
  Panel *this = (Panel *) self;
 
  release(this->accessoryView);
  release(this->contentView);
  release(this->resizeHandle);
  release(this->stackView);
 
  super(Object, self, dealloc);
}
 
#pragma mark - View
 
static bool acceptsKeyResponder(const View *self) {
  return false;
}
 
static void applyStyle(View *self, const Style *style) {
 
  super(View, self, applyStyle, style);
 
  Panel *this = (Panel *) self;
 
  const Inlet inlets[] = MakeInlets(
    MakeInlet("draggable", InletTypeBool, &this->isDraggable, NULL),
    MakeInlet("resizable", InletTypeBool, &this->isResizable, NULL)
  );
 
  $(self, bind, inlets, (Dictionary *) style->attributes);
}
 
static void awakeWithDictionary(View *self, const Dictionary *dictionary) {
 
  super(View, self, awakeWithDictionary, dictionary);
 
  Panel *this = (Panel *) self;
 
  const Inlet inlets[] = MakeInlets(
    MakeInlet("accessoryView", InletTypeView, &this->accessoryView, NULL),
    MakeInlet("contentView", InletTypeView, &this->contentView, NULL),
    MakeInlet("stackView", InletTypeView, &this->stackView, NULL)
  );
 
  $(self, bind, inlets, dictionary);
}
 
static View *init(View *self) {
  return (View *) $((Panel *) self, initWithFrame, NULL);
}
 
static void layoutSubviews(View *self) {
 
  const Panel *this = (Panel *) self;
 
  const SDL_Size size = $(this, contentSize);
 
  View *contentView = (View *) this->contentView;
 
  $(contentView, layoutWithSize, &size);
 
  super(View, self, layoutSubviews);
 
  View *resizeHandle = (View *) this->resizeHandle;
 
  resizeHandle->frame.x = self->frame.w - resizeHandle->frame.w;
  resizeHandle->frame.y = self->frame.h - resizeHandle->frame.h;
 
  $(resizeHandle, setVisibility,
    this->isResizable ? ViewVisibilityVisible : ViewVisibilityHidden);
}
 
#pragma mark - Control
 
static bool captureEvent(Control *self, const SDL_Event *event) {
 
  Panel *this = (Panel *) self;
 
  if (event->type == SDL_EVENT_MOUSE_BUTTON_DOWN) {
    if ($((View *) this->resizeHandle, didReceiveEvent, event)) {
      if (this->isResizable && !this->isDragging) {
        this->isResizing = true;
      }
      return true;
    }
  }
 
  if (event->type == SDL_EVENT_MOUSE_MOTION) {
 
    if (event->motion.state & SDL_BUTTON_LEFT) {
      self->state |= ControlStateHighlighted;
 
      if (this->isResizing || this->isDraggable) {
 
        // Motion is reported in points, which are fractional on high-density
        // displays. Carry the sub-point remainder between events so the integer
        // deltas applied to the frame sum exactly to the cursor's movement,
        // rather than truncating away a fraction each event and drifting behind.
        this->gestureResidual.x += event->motion.xrel;
        this->gestureResidual.y += event->motion.yrel;
 
        const int dx = (int) this->gestureResidual.x;
        const int dy = (int) this->gestureResidual.y;
 
        this->gestureResidual.x -= dx;
        this->gestureResidual.y -= dy;
 
        if (this->isResizing) {
          SDL_Size size = $((View *) self, size);
 
          size.w += dx;
          size.h += dy;
 
          $((View *) self, resize, &size);
 
        } else {
          this->isDragging = true;
 
          self->view.frame.x += dx;
          self->view.frame.y += dy;
 
          // Direct frame mutation outside of layout: refresh the render frame caches so
          // hit-testing for the remainder of this event batch sees the moved Panel.
          MVC_InvalidateRenderFrames();
        }
 
        return true;
      }
    } else {
      self->state &= ~ControlStateHighlighted;
      this->isResizing = this->isDragging = false;
      this->gestureResidual.x = this->gestureResidual.y = 0.f;
    }
  }
 
  return super(Control, self, captureEvent, event);
}
 
#pragma mark - Panel
 
static SDL_Size contentSize(const Panel *self) {
 
  const View *accessoryView = (View *) self->accessoryView;
  const View *contentView = (View *) self->contentView;
 
  SDL_Size size = $(contentView, sizeThatContains);
 
  if (accessoryView->visibility != ViewVisibilityHidden) {
    const SDL_Size accessorySize = $(accessoryView, sizeThatContains);
    size.h -= accessorySize.h + self->stackView->spacing;
  }
 
  return size;
}
 
static Panel *initWithFrame(Panel *self, const SDL_Rect *frame) {
 
  self = (Panel *) super(Control, self, initWithFrame, frame);
  if (self) {
    View *this = (View *) self;
 
    self->isDraggable = true;
    self->isResizable = true;
 
    self->stackView = $(alloc(StackView), initWithFrame, NULL);
    assert(self->stackView);
 
    $(this, addSubview, (View *) self->stackView);
 
    self->contentView = $(alloc(StackView), initWithFrame, NULL);
    assert(self->contentView);
 
    $((View *) self->contentView, addClassName, "contentView");
    $((View *) self->contentView, addClassName, "container");
 
    self->contentView->view.autoresizingMask |= ViewAutoresizingWidth;
 
    $((View *) self->stackView, addSubview, (View *) self->contentView);
 
    self->accessoryView = $(alloc(StackView), initWithFrame, NULL);
    assert(self->accessoryView);
 
    $((View *) self->accessoryView, addClassName, "accessoryView");
    $((View *) self->accessoryView, addClassName, "container");
 
 
    $((View *) self->stackView, addSubview, (View *) self->accessoryView);
 
    self->resizeHandle = $(alloc(ImageView), initWithImage, _resize);
    assert(self->resizeHandle);
 
    $((View *) self->resizeHandle, addClassName, "resizeHandle");
 
    self->resizeHandle->view.frame.w = DEFAULT_PANEL_RESIZE_HANDLE_SIZE;
    self->resizeHandle->view.frame.h = DEFAULT_PANEL_RESIZE_HANDLE_SIZE;
 
    $((View *) self, addSubview, (View *) self->resizeHandle);
  }
 
  return self;
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
  ((ObjectInterface *) clazz->interface)->dealloc = dealloc;
 
  ((ViewInterface *) clazz->interface)->acceptsKeyResponder = acceptsKeyResponder;
  ((ViewInterface *) clazz->interface)->applyStyle = applyStyle;
  ((ViewInterface *) clazz->interface)->awakeWithDictionary = awakeWithDictionary;
  ((ViewInterface *) clazz->interface)->init = init;
  ((ViewInterface *) clazz->interface)->layoutSubviews = layoutSubviews;
 
  ((ControlInterface *) clazz->interface)->captureEvent = captureEvent;
 
  ((PanelInterface *) clazz->interface)->contentSize = contentSize;
  ((PanelInterface *) clazz->interface)->initWithFrame = initWithFrame;
 
  _resize = $(alloc(Image), initWithBytes, resize_png, resize_png_len - 1, 1.f);
}
 
static void destroy(Class *clazz) {
  release(_resize);
}
 
Class *_Panel(void) {
  static Class *clazz;
  static Once once;
 
  do_once(&once, {
    clazz = _initialize(&(const ClassDef) {
      .name = "Panel",
      .superclass = _Control(),
      .instanceSize = sizeof(Panel),
      .interfaceSize = sizeof(PanelInterface),
      .initialize = initialize,
      .destroy = destroy,
    });
  });
 
  return clazz;
}
 
#undef _Class