eurorack/midi2cv/menu/menu.cc

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#include "menu.h"
#include <algorithm>
#include <u8g2.h>
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#define MENU_ITEM_HEIGHT 8
void Menu::render(u8g2_t* u8g2_, uint8_t xStart, uint8_t yStart, uint8_t width, uint8_t height)
{
this->width = width;
this->height = height;
uint8_t maxVisibleItems = height / MENU_ITEM_HEIGHT;
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uint8_t itemsToRender = std::min(maxVisibleItems, uint8_t(this->itemCount - currentScrollStart));
for (uint8_t i = 0; i < itemsToRender; i++) {
bool selected = this->selectedItem == (i + this->currentScrollStart);
uint8_t yPosition = yStart + i * MENU_ITEM_HEIGHT;
AbstractMenuItem* item = this->items[i + this->currentScrollStart];
u8g2_SetDrawColor(u8g2_, selected ? 1 : 0);
if (selected) {
u8g2_DrawBox(u8g2_, xStart, yPosition, width, MENU_ITEM_HEIGHT);
}
u8g2_SetDrawColor(u8g2_, !selected ? 1 : 0);
u8g2_DrawStr(u8g2_, xStart + 0, yPosition + MENU_ITEM_HEIGHT, item->get_label());
uint8_t valueStringWidth = u8g2_GetStrWidth(u8g2_, item->get_string_representation());
u8g2_DrawStr(u8g2_, xStart + width - valueStringWidth, yPosition + MENU_ITEM_HEIGHT, item->get_string_representation());
}
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}
void Menu::up()
{
if (this->selectedItem > 0) {
if (this->selectedItem - this->currentScrollStart == 1) { // keep scroll start one up
this->currentScrollStart--;
}
this->selectedItem--;
if (this->selectedItem == 0) {
this->currentScrollStart = 0;
}
}
}
void Menu::down()
{
uint8_t maxVisibleItems = height / MENU_ITEM_HEIGHT;
if (this->selectedItem < this->itemCount - 1) {
if (this->selectedItem - this->currentScrollStart == maxVisibleItems - 1) {
this->currentScrollStart++;
}
this->selectedItem++;
if (this->selectedItem >= this->itemCount - 1 - maxVisibleItems) { // last item
this->currentScrollStart = this->itemCount - 1 - maxVisibleItems;
}
}
}