CollectionView.c

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/*
 * ObjectivelyMVC: Object oriented MVC framework for OpenGL, SDL2 and GNU 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 "CollectionView.h"
 
const EnumName CollectionViewAxisNames[] = MakeEnumNames(
    MakeEnumAlias(CollectionViewAxisHorizontal, horizontal),
    MakeEnumAlias(CollectionViewAxisVertical, vertical)
);
 
#define _Class _CollectionView
 
#pragma mark - Object
 
static void dealloc(Object *self) {
 
    CollectionView *this = (CollectionView *) self;
 
    release(this->contentView);
    release(this->items);
    release(this->scrollView);
 
    super(Object, self, dealloc);
}
 
#pragma mark - View
 
static void applyStyle(View *self, const Style *style) {
 
    super(View, self, applyStyle, style);
 
    CollectionView *this = (CollectionView *) self;
 
    const Inlet inlets[] = MakeInlets(
        MakeInlet("axis", InletTypeEnum, &this->axis, (ident) CollectionViewAxisNames),
        MakeInlet("item-size", InletTypeSize, &this->itemSize, NULL),
        MakeInlet("item-spacing", InletTypeSize, &this->itemSpacing, NULL)
    );
 
    $(self, bind, inlets, (Dictionary *) style->attributes);
}
 
static View *init(View *self) {
    return (View *) $((CollectionView *) self, initWithFrame, NULL);
}
 
static void layoutSubviews(View *self) {
 
    CollectionView *this = (CollectionView *) self;
 
    super(View, self, layoutSubviews);
 
    const SDL_Rect bounds = $((View *) this->scrollView, bounds);
 
    int x = bounds.x, y = bounds.y;
 
    const Array *items = (Array *) this->items;
    for (size_t i = 0; i < items->count; i++) {
 
        CollectionItemView *item = (CollectionItemView *) $(items, objectAtIndex, i);
 
        item->view.frame.x = x;
        item->view.frame.y = y;
        item->view.frame.w = this->itemSize.w;
        item->view.frame.h = this->itemSize.h;
 
        switch (this->axis) {
            case CollectionViewAxisVertical:
                x += this->itemSize.w + this->itemSpacing.w;
                if (x + this->itemSize.w > bounds.w) {
                    y += this->itemSize.h + this->itemSpacing.h;
                    x = bounds.x;
                }
                break;
            case CollectionViewAxisHorizontal:
                y += this->itemSize.h + this->itemSpacing.h;
                if (y + this->itemSize.h > bounds.h) {
                    x += this->itemSize.w + this->itemSpacing.w;
                    y = bounds.y;
                }
                break;
        }
    }
}
 
static SDL_Size sizeThatFits(const View *self) {
 
    const CollectionView *this = (CollectionView *) self;
 
    return $(this, naturalSize);
}
 
#pragma mark - Control
 
static _Bool captureEvent(Control *self, const SDL_Event *event) {
 
    if (event->type == SDL_MOUSEBUTTONUP) {
 
        CollectionView *this = (CollectionView *) self;
 
        if ($((Control *) this->scrollView, isHighlighted) == false) {
            if ($((View *) this->contentView, didReceiveEvent, event)) {
 
                const SDL_Point point = {
                    .x = event->button.x,
                    .y = event->button.y
                };
 
                IndexPath *indexPath = $(this, indexPathForItemAtPoint, &point);
 
                const CollectionItemView *item = $(this, itemAtIndexPath, indexPath);
                if (item) {
 
                    switch (self->selection) {
                        case ControlSelectionNone:
                            break;
                        case ControlSelectionSingle:
                            if (item->isSelected == false) {
                                $(this, deselectAll);
                                $(this, selectItemAtIndexPath, indexPath);
                            }
                            break;
                        case ControlSelectionMultiple:
                            if (SDL_GetModState() & (KMOD_CTRL | KMOD_GUI)) {
                                if (item->isSelected) {
                                    $(this, deselectItemAtIndexPath, indexPath);
                                } else {
                                    $(this, selectItemAtIndexPath, indexPath);
                                }
                            } else {
                                $(this, deselectAll);
                                $(this, selectItemAtIndexPath, indexPath);
                            }
                            break;
                    }
 
                    if (this->delegate.didModifySelection) {
                        Array *selectionIndexPaths = $(this, selectionIndexPaths);
 
                        this->delegate.didModifySelection(this, selectionIndexPaths);
 
                        release(selectionIndexPaths);
                    }
                }
 
                release(indexPath);
                return true;
            }
        }
    }
 
    return super(Control, self, captureEvent, event);
}
 
#pragma mark - CollectionView
 
static void deselectAll_enumerate(const Array *array, ident obj, ident data) {
    $((CollectionItemView *) obj, setSelected, false);
}
 
static void deselectAll(CollectionView *self) {
    $((Array *) self->items, enumerateObjects, deselectAll_enumerate, NULL);
}
 
static void deselectItemAtIndexPath(CollectionView *self, const IndexPath *indexPath) {
 
    if (indexPath) {
        CollectionItemView *item = $(self, itemAtIndexPath, indexPath);
        if (item) {
            $(item, setSelected, false);
            $(self->contentView, invalidateStyle);
        }
    }
}
 
static void deselectItemsAtIndexPaths_enumerate(const Array *array, ident obj, ident data) {
    $((CollectionItemView *) obj, setSelected, false);
}
 
static void deselectItemsAtIndexPaths(CollectionView *self, const Array *indexPaths) {
 
    if (indexPaths) {
        $(indexPaths, enumerateObjects, deselectItemsAtIndexPaths_enumerate, self);
    }
}
 
static IndexPath *indexPathForItemAtPoint(const CollectionView *self, const SDL_Point *point) {
 
    if (self->itemSize.w && self->itemSize.h) {
 
        const SDL_Rect frame = $(self->contentView, renderFrame);
 
        const int itemWidth = self->itemSize.w + self->itemSpacing.w;
        const int itemHeight = self->itemSize.h + self->itemSpacing.h;
 
        const int rows = max(1, frame.h / itemHeight);
        const int cols = max(1, frame.w / itemWidth);
 
        const int x = point->x - frame.x;
        const int y = point->y - frame.y;
 
        const int row = y / itemHeight;
        const int col = x / itemWidth;
 
        int index;
        switch (self->axis) {
            case CollectionViewAxisVertical:
                index = row * cols + col;
                break;
            case CollectionViewAxisHorizontal:
                index = col * rows + row;
                break;
        }
 
        if (index < (int) self->items->array.count) {
            return $(alloc(IndexPath), initWithIndex, index);
        }
    }
 
    return NULL;
}
 
static IndexPath *indexPathForItem(const CollectionView *self, const CollectionItemView *item) {
 
    const ssize_t index = $((Array *) self->items, indexOfObject, (ident) item);
    if (index > -1) {
        return $(alloc(IndexPath), initWithIndex, index);
    }
 
    return NULL;
}
 
static CollectionView *initWithFrame(CollectionView *self, const SDL_Rect *frame) {
 
    self = (CollectionView *) super(Control, self, initWithFrame, frame);
    if (self) {
 
        self->items = $$(MutableArray, array);
 
        self->contentView = $(alloc(View), initWithFrame, NULL);
        assert(self->contentView);
 
        $(self->contentView, addClassName, "contentView");
        $(self->contentView, addClassName, "container");
 
        self->scrollView = $(alloc(ScrollView), initWithFrame, NULL);
        assert(self->scrollView);
 
        $(self->scrollView, setContentView, self->contentView);
 
        $((View *) self, addSubview, (View *) self->scrollView);
    }
 
    return self;
}
 
static CollectionItemView *itemAtIndexPath(const CollectionView *self, const IndexPath *indexPath) {
 
    if (indexPath) {
        const Array *items = (Array *) self->items;
        const size_t index = $(indexPath, indexAtPosition, 0);
 
        if (index < items->count) {
            return $(items, objectAtIndex, index);
        }
    }
 
    return NULL;
}
 
static SDL_Size naturalSize(const CollectionView *self) {
 
    ViewPadding padding = MakePadding(0, 0, 0, 0);
    padding = AddPadding(padding, ((View *) self)->padding);
    padding = AddPadding(padding, ((View *) self->scrollView)->padding);
    padding = AddPadding(padding, ((View *) self->contentView)->padding);
 
    SDL_Size size = MakeSize(padding.left + padding.right, padding.top + padding.bottom);
 
    const SDL_Rect bounds = $((View *) self->scrollView->contentView, bounds);
 
    switch (self->axis) {
        case CollectionViewAxisVertical: {
            int itemsPerRow = 1;
            int w = bounds.w;
            while (w > 0) {
                w -= self->itemSize.w;
                itemsPerRow++;
                if (w - self->itemSpacing.w < 0) {
                    break;
                }
                w -= self->itemSpacing.w;
            }
            const int rows = ceilf(self->items->array.count / (float) itemsPerRow);
            size.w += max(self->itemSize.w, bounds.w);
            size.h += rows * (self->itemSize.h + self->itemSpacing.h);
        }
            break;
        case CollectionViewAxisHorizontal:{
            int itemsPerCol = 1;
            int h = bounds.h;
            while (h > 0) {
                h -= self->itemSize.h;
                itemsPerCol++;
                if (h - self->itemSpacing.h < 0) {
                    break;
                }
                h -= self->itemSpacing.h;
            }
            const int cols = ceilf(self->items->array.count / (float) itemsPerCol);
            size.w += cols * (self->itemSize.w + self->itemSpacing.w);
            size.h += max(self->itemSize.h, bounds.h);
        }
            break;
    }
 
    return size;
}
 
static void reloadData_removeItems(const Array *array, ident obj, ident data) {
    $((View *) data, removeSubview, (View *) obj);
}
 
static void reloadData(CollectionView *self) {
 
    assert(self->dataSource.numberOfItems);
    assert(self->delegate.itemForObjectAtIndexPath);
 
    $((Array *) self->items, enumerateObjects, reloadData_removeItems, self->contentView);
    $(self->items, removeAllObjects);
 
    const size_t numberOfItems = self->dataSource.numberOfItems(self);
    for (size_t i = 0; i < numberOfItems; i++) {
 
        IndexPath *indexPath = $(alloc(IndexPath), initWithIndex, i);
 
        CollectionItemView *item = self->delegate.itemForObjectAtIndexPath(self, indexPath);
        assert(item);
 
        $(self->items, addObject, item);
        $(self->contentView, addSubview, (View *) item);
 
        release(item);
        release(indexPath);
    }
 
    ((View *) self)->needsLayout = true;
}
 
static void selectAll_enumerate(const Array *array, ident obj, ident data) {
    $((CollectionItemView *) obj, setSelected, true);
}
 
static void selectAll(CollectionView *self) {
    $((Array *) self->items, enumerateObjects, selectAll_enumerate, NULL);
}
 
static Array *selectionIndexPaths(const CollectionView *self) {
 
    MutableArray *array = $$(MutableArray, array);
 
    const Array *items = (Array *) self->items;
    for (size_t i = 0; i < items->count; i++) {
 
        const CollectionItemView *item = $(items, objectAtIndex, i);
        if (item->isSelected) {
 
            IndexPath *indexPath = $(self, indexPathForItem, item);
            $(array, addObject, indexPath);
 
            release(indexPath);
        }
    }
 
    return (Array *) array;
}
 
static void selectItemAtIndexPath(CollectionView *self, const IndexPath *indexPath) {
 
    if (indexPath) {
        CollectionItemView *item = $(self, itemAtIndexPath, indexPath);
        if (item) {
            $(item, setSelected, true);
            $(self->contentView, invalidateStyle);
        }
    }
}
 
static void selectItemsAtIndexPaths_enumerate(const Array *array, ident obj, ident data) {
    $((CollectionView *) data, selectItemAtIndexPath, (IndexPath *) obj);
}
 
static void selectItemsAtIndexPaths(CollectionView *self, const Array *indexPaths) {
 
    if (indexPaths) {
        $(indexPaths, enumerateObjects, selectItemsAtIndexPaths_enumerate, self);
    }
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
    ((ObjectInterface *) clazz->interface)->dealloc = dealloc;
 
    ((ViewInterface *) clazz->interface)->applyStyle = applyStyle;
    ((ViewInterface *) clazz->interface)->init = init;
    ((ViewInterface *) clazz->interface)->layoutSubviews = layoutSubviews;
    ((ViewInterface *) clazz->interface)->sizeThatFits = sizeThatFits;
 
    ((ControlInterface *) clazz->interface)->captureEvent = captureEvent;
 
    ((CollectionViewInterface *) clazz->interface)->deselectAll = deselectAll;
    ((CollectionViewInterface *) clazz->interface)->deselectItemAtIndexPath = deselectItemAtIndexPath;
    ((CollectionViewInterface *) clazz->interface)->deselectItemsAtIndexPaths = deselectItemsAtIndexPaths;
    ((CollectionViewInterface *) clazz->interface)->indexPathForItem = indexPathForItem;
    ((CollectionViewInterface *) clazz->interface)->indexPathForItemAtPoint = indexPathForItemAtPoint;
    ((CollectionViewInterface *) clazz->interface)->initWithFrame = initWithFrame;
    ((CollectionViewInterface *) clazz->interface)->itemAtIndexPath = itemAtIndexPath;
    ((CollectionViewInterface *) clazz->interface)->naturalSize = naturalSize;
    ((CollectionViewInterface *) clazz->interface)->reloadData = reloadData;
    ((CollectionViewInterface *) clazz->interface)->selectAll = selectAll;
    ((CollectionViewInterface *) clazz->interface)->selectionIndexPaths = selectionIndexPaths;
    ((CollectionViewInterface *) clazz->interface)->selectItemAtIndexPath = selectItemAtIndexPath;
    ((CollectionViewInterface *) clazz->interface)->selectItemsAtIndexPaths = selectItemsAtIndexPaths;
}
 
Class *_CollectionView(void) {
    static Class *clazz;
    static Once once;
 
    do_once(&once, {
        clazz = _initialize(&(const ClassDef) {
            .name = "CollectionView",
            .superclass = _Control(),
            .instanceSize = sizeof(CollectionView),
            .interfaceOffset = offsetof(CollectionView, interface),
            .interfaceSize = sizeof(CollectionViewInterface),
            .initialize = initialize,
        });
    });
 
    return clazz;
}
 
#undef _Class