DVX_GUI/listhelp/listHelp.c

290 lines
8.4 KiB
C

// listHelp.c -- Shared list/dropdown helper functions
//
// Implements dropdown arrow drawing, item length scanning, keyboard
// navigation, and popup list painting used by ListBox, Dropdown,
// ComboBox, ListView, and TreeView widgets.
#include "listHelp.h"
#include "../texthelp/textHelp.h"
#include <string.h>
// ============================================================
// widgetDrawDropdownArrow
// ============================================================
//
// Draws a small downward-pointing filled triangle (7, 5, 3, 1 pixels
// wide across 4 rows) centered at the given position. Used by both
// Dropdown and ComboBox for the drop button arrow glyph.
void widgetDrawDropdownArrow(DisplayT *d, const BlitOpsT *ops, int32_t centerX, int32_t centerY, uint32_t color) {
for (int32_t i = 0; i < 4; i++) {
drawHLine(d, ops, centerX - 3 + i, centerY + i, 7 - i * 2, color);
}
}
// ============================================================
// widgetMaxItemLen
// ============================================================
//
// Scans an array of string items and returns the maximum strlen.
// Shared by ListBox, Dropdown, and ComboBox to cache the widest
// item length for calcMinSize without duplicating the loop.
int32_t widgetMaxItemLen(const char **items, int32_t count) {
int32_t maxLen = 0;
for (int32_t i = 0; i < count; i++) {
int32_t slen = (int32_t)strlen(items[i]);
if (slen > maxLen) {
maxLen = slen;
}
}
return maxLen;
}
// ============================================================
// widgetNavigateIndex
// ============================================================
//
// Shared keyboard navigation for list-like widgets (ListBox, Dropdown,
// ListView, etc.). Encapsulates the Up/Down/Home/End/PgUp/PgDn logic
// so each widget doesn't have to reimplement index clamping.
//
// Key values use the 0x100 flag to mark extended scan codes (arrow
// keys, Home, End, etc.) -- this is the DVX convention for passing
// scan codes through the same int32_t channel as ASCII values.
//
// Returns -1 for unrecognized keys so callers can check whether the
// key was consumed.
int32_t widgetNavigateIndex(int32_t key, int32_t current, int32_t count, int32_t pageSize) {
if (key == (0x50 | 0x100)) {
// Down arrow
if (current < count - 1) {
return current + 1;
}
return current < 0 ? 0 : current;
}
if (key == (0x48 | 0x100)) {
// Up arrow
if (current > 0) {
return current - 1;
}
return current < 0 ? 0 : current;
}
if (key == (0x47 | 0x100)) {
// Home
return 0;
}
if (key == (0x4F | 0x100)) {
// End
return count - 1;
}
if (key == (0x51 | 0x100)) {
// Page Down
int32_t n = current + pageSize;
return n >= count ? count - 1 : n;
}
if (key == (0x49 | 0x100)) {
// Page Up
int32_t n = current - pageSize;
return n < 0 ? 0 : n;
}
return -1;
}
// ============================================================
// widgetTypeAheadSearch
// ============================================================
int32_t widgetTypeAheadSearch(char ch, const char **items, int32_t itemCount, int32_t currentIdx) {
if (itemCount <= 0 || !items) {
return -1;
}
char upper = (ch >= 'a' && ch <= 'z') ? ch - 32 : ch;
// Search forward from currentIdx+1, wrapping around
for (int32_t i = 1; i <= itemCount; i++) {
int32_t idx = (currentIdx + i) % itemCount;
char first = items[idx][0];
if (first >= 'a' && first <= 'z') {
first -= 32;
}
if (first == upper) {
return idx;
}
}
return -1;
}
// ============================================================
// widgetPaintPopupList
// ============================================================
//
// Shared popup list painting for Dropdown and ComboBox.
void widgetPaintPopupList(DisplayT *d, const BlitOpsT *ops, const BitmapFontT *font, const ColorSchemeT *colors, int32_t popX, int32_t popY, int32_t popW, int32_t popH, const char **items, int32_t itemCount, int32_t hoverIdx, int32_t scrollPos) {
bool hasScrollbar = (itemCount > DROPDOWN_MAX_VISIBLE);
int32_t visibleItems = popH / font->charHeight;
int32_t listW = hasScrollbar ? popW - POPUP_SCROLLBAR_W : popW;
// Draw popup border (covers item area only, not scrollbar)
BevelStyleT bevel;
bevel.highlight = colors->windowHighlight;
bevel.shadow = colors->windowShadow;
bevel.face = colors->contentBg;
bevel.width = 2;
drawBevel(d, ops, popX, popY, listW, popH, &bevel);
// Draw items
int32_t textX = popX + TEXT_INPUT_PAD;
int32_t textY = popY + 2;
int32_t textW = listW - TEXT_INPUT_PAD * 2 - 4;
for (int32_t i = 0; i < visibleItems && (scrollPos + i) < itemCount; i++) {
int32_t idx = scrollPos + i;
int32_t iy = textY + i * font->charHeight;
uint32_t ifg = colors->contentFg;
uint32_t ibg = colors->contentBg;
if (idx == hoverIdx) {
ifg = colors->menuHighlightFg;
ibg = colors->menuHighlightBg;
rectFill(d, ops, popX + 2, iy, textW + TEXT_INPUT_PAD * 2, font->charHeight, ibg);
}
drawText(d, ops, font, textX, iy, items[idx], ifg, ibg, false);
}
// Draw scrollbar
if (hasScrollbar) {
wmDrawVScrollbarAt(d, ops, colors, popX + listW, popY, popH, scrollPos, visibleItems, itemCount);
}
}
// ============================================================
// widgetPopupScrollbarClick
// ============================================================
bool widgetPopupScrollbarClick(int32_t x, int32_t y, int32_t popX, int32_t popY, int32_t popW, int32_t popH, int32_t itemCount, int32_t visibleItems, int32_t *scrollPos) {
if (itemCount <= DROPDOWN_MAX_VISIBLE) {
return false;
}
int32_t listW = popW - POPUP_SCROLLBAR_W;
int32_t sbX = popX + listW;
if (x < sbX || x >= sbX + POPUP_SCROLLBAR_W) {
return false;
}
int32_t maxScroll = itemCount - visibleItems;
int32_t relY = y - popY;
if (relY < POPUP_SCROLLBAR_W) {
// Up arrow
if (*scrollPos > 0) {
(*scrollPos)--;
}
} else if (relY >= popH - POPUP_SCROLLBAR_W) {
// Down arrow
if (*scrollPos < maxScroll) {
(*scrollPos)++;
}
} else {
// Trough — page up/down based on which side of thumb
int32_t trackLen = popH - POPUP_SCROLLBAR_W * 2;
int32_t thumbSize = (int32_t)(((int64_t)visibleItems * trackLen) / itemCount);
if (thumbSize < POPUP_SCROLLBAR_W) {
thumbSize = POPUP_SCROLLBAR_W;
}
int32_t thumbPos = 0;
if (maxScroll > 0) {
thumbPos = (int32_t)(((int64_t)(*scrollPos) * (trackLen - thumbSize)) / maxScroll);
}
int32_t clickInTrack = relY - POPUP_SCROLLBAR_W;
if (clickInTrack < thumbPos) {
// Page up
*scrollPos -= visibleItems;
if (*scrollPos < 0) {
*scrollPos = 0;
}
} else if (clickInTrack >= thumbPos + thumbSize) {
// Page down
*scrollPos += visibleItems;
if (*scrollPos > maxScroll) {
*scrollPos = maxScroll;
}
}
}
return true;
}
// ============================================================
// widgetDropdownPopupRect
// ============================================================
//
// Calculates the screen rectangle for a dropdown/combobox popup list.
// Shared between Dropdown and ComboBox since they have identical
// popup positioning logic.
void widgetDropdownPopupRect(WidgetT *w, const BitmapFontT *font, int32_t contentH, int32_t itemCount, int32_t *popX, int32_t *popY, int32_t *popW, int32_t *popH) {
int32_t visibleItems = itemCount;
if (visibleItems > DROPDOWN_MAX_VISIBLE) {
visibleItems = DROPDOWN_MAX_VISIBLE;
}
if (visibleItems < 1) {
visibleItems = 1;
}
*popX = w->x;
*popW = w->w;
*popH = visibleItems * font->charHeight + 4;
// Add scrollbar width when list exceeds visible area
if (itemCount > DROPDOWN_MAX_VISIBLE) {
*popW += POPUP_SCROLLBAR_W;
}
if (w->y + w->h + *popH <= contentH) {
*popY = w->y + w->h;
} else {
*popY = w->y - *popH;
if (*popY < 0) {
*popY = 0;
}
}
}