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CommandStation-EX/LCDDisplay.cpp
2021-02-19 12:42:35 +00:00

119 lines
3.7 KiB
C++

/*
* © 2021, Chris Harlow, Neil McKechnie. All rights reserved.
*
* This file is part of CommandStation-EX
*
* This is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* It is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with CommandStation. If not, see <https://www.gnu.org/licenses/>.
*/
// CAUTION: the device dependent parts of this class are created in the .ini using LCD_Implementation.h
#include "LCDDisplay.h"
void LCDDisplay::clear() {
clearNative();
for (byte row=0;row<MAX_LCD_ROWS; row++) rowBuffer[row][0]='\0';
topRow=-1; // loop2 will fill from row 0
}
void LCDDisplay::setRow(byte line) {
hotRow=line;
hotCol=0;
}
size_t LCDDisplay::write(uint8_t b) {
if (hotRow>=MAX_LCD_ROWS || hotCol>=MAX_LCD_COLS) return -1;
rowBuffer[hotRow][hotCol]=b;
hotCol++;
rowBuffer[hotRow][hotCol]=0;
return 1;
}
void LCDDisplay::loop() {
if (!lcdDisplay) return;
lcdDisplay->loop2(false);
}
LCDDisplay *LCDDisplay::loop2(bool force)
{
static int rowFirst = -1;
static int rowNext = 0;
static int charIndex = 0;
static char buffer[MAX_LCD_COLS+1];
static char *bptr = 0;
static bool done = false;
unsigned long currentMillis = millis();
if ((!force) && (currentMillis - lastScrollTime) < LCD_SCROLL_TIME)
return NULL;
do {
if (bptr == 0) {
// Find a line of data to write to the screen.
if (!done) {
if (rowFirst < 0) rowFirst = rowNext;
// Skip blank rows
while (rowBuffer[rowNext][0] == 0) {
rowNext = (rowNext + 1) % MAX_LCD_ROWS;
if (rowNext == rowFirst) {
done = true; // All lines done
break;
}
}
}
if (!done) {
// Non-blank line found, so copy it.
for (int i=0; i<MAX_LCD_COLS+1; i++)
buffer[i] = rowBuffer[rowNext][i];
} else
buffer[0] = '\0'; // Empty line
setRowNative(slot); // Set position for display
charIndex = 0;
bptr = &buffer[0];
} else {
// Write next character, or a space to erase current position.
char ch = *bptr;
if (ch) {
writeNative(ch);
bptr++;
} else
writeNative(' ');
if (++charIndex >= MAX_LCD_COLS) {
// Screen slot completed, move to next one
slot++;
bptr = 0;
if (!done) {
rowNext = (rowNext + 1) % MAX_LCD_ROWS;
if (rowNext == rowFirst) done = true;
}
}
if (slot >= lcdRows) {
// Last slot finished, reset ready for next update.
slot = 0;
done = false;
rowFirst = -1;
lastScrollTime = currentMillis;
return NULL;
}
}
} while (force);
return NULL;
}