ScreenUi.cpp

/**
 * ScreenUi
 * A toolkit for building character based user interfaces on small displays.
 * Copyright (c) 2012 Jason von Nieda <jason@vonnieda.org>
 *
 * This file is part of ScreenUi.
 *
 * ScreenUi 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.
 *
 * ScreenUi 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 ScreenUi.  If not, see <http://www.gnu.org/licenses/>. 
 */

#include <ScreenUi.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>

#ifdef SCREENUI_DEBUG
#include <WProgram.h>
#endif

void* operator new(size_t size) { return malloc(size); }
void operator delete(void* ptr) { free(ptr); }

// TODO: Change to PROGMEM
uint8_t charCheckmark[] =     {0,     // B00000
                               0,     // B00000
                               1,     // B00001
                               2,     // B00010
                               20,    // B10100
                               8,     // B01000
                               0,     // B00000
                               0};    // B00000

                               
////////////////////////////////////////////////////////////////////////////////
// Screen
////////////////////////////////////////////////////////////////////////////////
Screen::Screen(uint8_t width, uint8_t height) {
  setSize(width, height);
  cleared_ = false;
  focusHolder_ = NULL;
  focusHolderSelected_ = false;
  createCustomChar(7, charCheckmark);
  annoyingBugWorkedAround_ = false;
}

void Screen::update() {
  if (!cleared_) {
    clear();
    cleared_ = true;
  }
  Container::update(this);
  int x, y;
  bool selected, cancelled;
  getInputDeltas(&x, &y, &selected, &cancelled);
  Component *oldFocusHolder = focusHolder_;
  if (x || y || selected || cancelled) {
    if (focusHolderSelected_) {
      focusHolderSelected_ = focusHolder_->handleInputEvent(x, y, selected, cancelled);
    }
    else {
      if (selected) {
        focusHolderSelected_ = focusHolder_->handleInputEvent(x, y, selected, cancelled);
      }
      else if (x || y) {
        // TODO: Make axis x or y configurable.
        // TODO: consider making the last widget in the screen the end of focus,
        // so that you don't cycle back to the top but instead lock at the end
        // and vice-verse. Maybe make this configurable.
        if (y > 0) {
          focusHolder_ = nextFocusHolder(focusHolder_, false);
          if (!focusHolder_) {
            focusHolder_ = nextFocusHolder(focusHolder_, false);
          }
        }
        else if (y < 0) {
          focusHolder_ = nextFocusHolder(focusHolder_, true);
          if (!focusHolder_) {
            focusHolder_ = nextFocusHolder(focusHolder_, true);
          }
        }
      }
    }
  }
  if (focusHolder_ == NULL) {
    focusHolder_ = nextFocusHolder(focusHolder_, false);
  }
  if (oldFocusHolder != focusHolder_) {
    if (oldFocusHolder) {
      oldFocusHolder->repaint();
    }
    focusHolder_->repaint();
  }
  paint(this);
  moveCursor(cursorX_, cursorY_);
  
  // TODO: Bug I can't figure out. If we use the dirtyness system, the first paint
  // fails to draw anything to the screen and then subsequent ones don't get called
  // because they aren't dirty. The second paint works fine. 
  // Adding repaint() here allows us to paint during the second loop which gets
  // everything into a state where it works great, but I can't figure out why.
  // It doesn't seem to have to do with timing or the clear().
  if (!annoyingBugWorkedAround_) {
    repaint();
    annoyingBugWorkedAround_ = true;
  }
}

////////////////////////////////////////////////////////////////////////////////
// Container
////////////////////////////////////////////////////////////////////////////////
Container::Container() {
  components_ = NULL;
  componentsLength_ = 0;
  componentCount_ = 0;
}

Container::~Container() {
  if (components_) {
    free(components_);
  }
}

void Container::update(Screen *screen) {
  if (!firstUpdateCompleted_) {
    offsetChildren(0, y_);
    firstUpdateCompleted_ = true;
  }
  for (int i = 0; i < componentCount_; i++) {
    components_[i]->update(screen);
  }
}

void Container::paint(Screen *screen) {
  for (int i = 0; i < componentCount_; i++) {
    if (components_[i]->dirty()) {
      components_[i]->paint(screen);
    }
  }
}

void Container::repaint() {
  for (int i = 0; i < componentCount_; i++) {
    components_[i]->repaint();
  }
}

void Container::add(Component *component, int8_t x, int8_t y) {
  if (!components_ || componentsLength_ <= componentCount_) {
    componentsLength_ = (componentsLength_ * 2) + 1;
    components_ = (Component**) realloc(components_, componentsLength_ * sizeof(Component*));
  }
  components_[componentCount_++] = component;
  if (firstUpdateCompleted_) {
    // TODO: if the first update has already completed we need to update
    // incoming components locations as they are added
  }
  component->setLocation(x, y);
  component->repaint();
}

void Container::offsetChildren(int x, int y) {
  for (int i = 0; i < componentCount_; i++) {
    Component *c = components_[i];
    /*
    Serial.print("Moving ");
    Serial.print(c->description());
    Serial.print(" from ");
    Serial.print(c->x(), DEC);
    Serial.print(", ");
    Serial.print(c->y(), DEC);
    Serial.print(" to ");
    Serial.print(c->x() + x, DEC);
    Serial.print(", ");
    Serial.println(c->y() + y, DEC);
    */
    c->setLocation(c->x() + x, c->y() + y);
  }
}

Component *Container::nextFocusHolder(Component *focusHolder, bool reverse) {
  bool focusHolderFound = false;
  return nextFocusHolder(focusHolder, reverse, &focusHolderFound);
}

Component *Container::nextFocusHolder(Component *focusHolder, bool reverse, bool *focusHolderFound) {
  for (int i = (reverse ? componentCount_ - 1 : 0); (reverse ? (i > 0) : (i < componentCount_)); (reverse ? i-- : i++)) {
    Component *c = components_[i];
    if (c->isContainer()) {
      Component *next = ((Container*) c)->nextFocusHolder(focusHolder, reverse, focusHolderFound);
      if (next) {
        return next;
      }
    }
    else {
      if (c->acceptsFocus()) {
        if (!focusHolder || *focusHolderFound) {
          return c;
        }
        else if (c == focusHolder) {
          *focusHolderFound = true;
        }
      }
    }
  }
  return NULL;
}

bool Container::dirty() {
  for (int i = 0; i < componentCount_; i++) {
    if (components_[i]->dirty()) {
      return true;
    }
  }
  return false;
}

bool Container::contains(Component *component) {
  for (int i = 0; i < componentCount_; i++) {
    Component *c = components_[i];
    if (c == component) {
      return true;
    }
    else if (c->isContainer()) {
      if (((Container*) c)->contains(component)) {
        return true;
      }
    }
  }
  return false;
}

////////////////////////////////////////////////////////////////////////////////
// Component
////////////////////////////////////////////////////////////////////////////////

void Component::paint(Screen *screen) {
  dirty_ = false;
}

bool Component::dirty() {
  return dirty_;
}

////////////////////////////////////////////////////////////////////////////////
// Label
////////////////////////////////////////////////////////////////////////////////
Label::Label(const char *text) {
  setSize(0, 1);
  setText(text);
  captured_ = false;
  dirtyWidth_ = 0;
}

void Label::paint(Screen *screen) {
  Component::paint(screen);
  
  // Label does not accept focus, but Button, Checkbox and List are all
  // subclasses that want to share the same text drawing system, so we
  // just account for it here.
  if (acceptsFocus()) {
    if (screen->focusHolder() == this) {
      if (captured_) {
        screen->draw(x_, y_, ">");
        screen->draw(x_ + width_ + 1, y_, "<");
      }
      else {
        screen->draw(x_, y_, "<");
        screen->draw(x_ + width_ + 1, y_, ">");
      }
    }
    else {
      screen->draw(x_, y_, "[");
      screen->draw(x_ + width_ + 1, y_, "]");
    }
  }
  
  screen->draw(x_ + (acceptsFocus() ? 1 : 0), y_, text_);
  if (dirtyWidth_) {
    for (int i = 0; i < dirtyWidth_ - width_; i++) {
      screen->draw(x_ + width_ + i + (acceptsFocus() ? 2 : 0), y_, " ");
    }
    dirtyWidth_ = 0;
  }
}

void Label::setText(const char *text) {
  text_ = (char*) text;
  uint8_t newWidth = strlen(text);
  if (newWidth < width_) {
    dirtyWidth_ = width_;
  }
  width_ = newWidth;
  repaint();
}

////////////////////////////////////////////////////////////////////////////////
// Button
////////////////////////////////////////////////////////////////////////////////
Button::Button(const char *text) : Label(text) {
  setText(text);
  pressed_ = false;
}

void Button::update(Screen *screen) {
  pressed_ = false;
}

bool Button::handleInputEvent(int x, int y, bool selected, bool cancelled) {
  pressed_ = selected;
  return false;
}

////////////////////////////////////////////////////////////////////////////////
// Checkbox
////////////////////////////////////////////////////////////////////////////////

Checkbox::Checkbox() : Label(" ") {
  checked_ = false;
}

bool Checkbox::handleInputEvent(int x, int y, bool selected, bool cancelled) {
  if (selected) {
    checked_ = !checked_;
    // Not James Bond. The 8th custom character location. By using a non-zero
    // location we can still send it via a string, which means we can still
    // be a Label instead of having a custom paint routine.
    setText(checked_ ? "\007" : " ");
    repaint();
  }
  return false;
}

////////////////////////////////////////////////////////////////////////////////
// List
////////////////////////////////////////////////////////////////////////////////

List::List(uint8_t maxItems) : Label(NULL) {
  items_ = (char **) malloc(maxItems * (sizeof(char*)));
  itemCount_ = 0;
  selectedIndex_ = 0;
  captured_ = false;
}

List::~List() {
  free(items_);
}

void List::addItem(const char *item) {
  items_[itemCount_++] = (char*) item;
  if (text_ == NULL) {
    setText(selectedItem());
  }
}

void List::setSelectedIndex(uint8_t selectedIndex) {
  selectedIndex_ = selectedIndex;
  setText(selectedItem());
  repaint();
}

bool List::handleInputEvent(int x, int y, bool selected, bool cancelled) {
  if (captured_ && y) {
    if (y < 0) {
      setSelectedIndex(max(selectedIndex_ + y, 0));
    }
    else {
      setSelectedIndex(min(selectedIndex_ + y, itemCount_ - 1));
    }
  }
  if (selected) {
    captured_ = !captured_;
    repaint();
  }
  return captured_;
}

////////////////////////////////////////////////////////////////////////////////
// Spinner
////////////////////////////////////////////////////////////////////////////////

Spinner::Spinner(int value, int low, int high, int increment, bool rollover) : Label(NULL) {
  value_ = value;
  low_ = low;
  high_ = high;
  increment_ = increment;
  rollover_ = rollover;
  sprintf(buffer_, "%d", value_);
  setText(buffer_);
}

int Spinner::intValue() {
  return value_;
}

bool Spinner::handleInputEvent(int x, int y, bool selected, bool cancelled) {
  if (captured_ && y) {
    value_ += (y * increment_);
    if (value_ < low_) {
      value_ = rollover_ ? high_ : low_;
    }
    else if (value_ > high_) {
      value_ = rollover_ ? low_ : high_;
    }
    sprintf(buffer_, "%d", value_);
    setText(buffer_);
    repaint();
  }
  if (selected) {
    captured_ = !captured_;
    repaint();
  }
}

////////////////////////////////////////////////////////////////////////////////
// Input
////////////////////////////////////////////////////////////////////////////////

// TODO: trim incoming text and after each return, right justify the text
Input::Input(char *text) : Label((const char*) text) {
  position_ = 0;
  selecting_ = false;
  charSet_ = &defaultCharSet;
}

void Input::setText(char *text) {
  Label::setText((const char *) text);
  position_ = 0;
  selecting_ = false;
  repaint();
}

void Input::paint(Screen *screen) {
  Label::paint(screen);
  screen->setCursorVisible(captured_ && selecting_);
  screen->setBlink(captured_ && !selecting_);
  screen->setCursorLocation(x_ + position_ + 1, y_);
}

bool Input::handleInputEvent(int x, int y, bool selected, bool cancelled) {
  // If the input is captured and there has been a scroll event we're going to
  // either change the position or change the selection.
  if (captured_ && y) {
    // If we're changing the selection, scroll through the character set.
    if (selecting_) {
      // TODO: replace this with a selectable character set that makes more
      // sense
      if (y < 0) {
        text_[position_] = charSet_->charAt(max(charSet_->indexOf(text_[position_]) + y, 0));
      }
      else {
        text_[position_] = charSet_->charAt(min(charSet_->indexOf(text_[position_]) + y, charSet_->size() - 1));
      }
    }
    // Otherwise we are changing the position. If the position is moving before
    // or after the field we release the input.
    else {
      position_ += y;
      if (position_ < 0 || position_ >= width_) {
        captured_ = false;
      }
    }
    repaint();
  }
  // If there has been a click we will either capture the input, 
  // start selection or end selection.
  if (selected) {
    // If input is captured we will start or end selection
    // input.
    if (captured_) {
      selecting_ = !selecting_;
    }
    // Capture the input
    else {
      captured_ = true;
      position_ = 0;
      selecting_ = false;
    }
    repaint();
  }
  return captured_;
}


////////////////////////////////////////////////////////////////////////////////
// IntegerInput
////////////////////////////////////////////////////////////////////////////////
IntegerInput::IntegerInput(long value, unsigned char width, unsigned char base) : Input(NULL) {
  signed_ = true;
  base_ = base;
  if (!width) {
    // count the digits
  }
}

IntegerInput::IntegerInput(unsigned long value, unsigned char width, unsigned char base) : Input(NULL) {
  signed_ = false;
  base_ = base;
  if (!width) {
    // count the digits
  }
}

////////////////////////////////////////////////////////////////////////////////
// ScrollContainer
////////////////////////////////////////////////////////////////////////////////

ScrollContainer::ScrollContainer(Screen *screen, uint8_t width, uint8_t height) {
  setSize(width, height);
  screen_ = screen;
  clearLine = (char*) malloc(width + 1);
  memset(clearLine, ' ', width);
  clearLine[width] = NULL;
  firstUpdateCompleted_ = false;
}

ScrollContainer::~ScrollContainer() {
  free(clearLine);
}

bool ScrollContainer::dirty() {
  if (Container::dirty()) {
    return true;
  }
  return scrollNeeded();
}

bool ScrollContainer::scrollNeeded() {
  // see if the focus holder has changed since the last check
  Component *focusHolder = screen_->focusHolder();
  if (lastFocusHolder_ != focusHolder) {
    // it has, so see if the new focus holder is one of ours
    if (contains(focusHolder)) {
      // it is, so we need to be sure it's visible, which means it's
      // y position plus height has to be within our window of visibility
      // our window of visbility is our y_ + row_ to y_ + row_ + height_
      uint8_t yStart = y_;
      uint8_t yEnd = y_ + height_ - 1;
      if (focusHolder->y() < yStart || focusHolder->y() > yEnd) {
        // it is not currently visible, so we are dirty
        return true;
      }
    }
  }
  return false;
}

void ScrollContainer::paint(Screen *screen) {
  Component::paint(screen);
  if (scrollNeeded()) {
    // we need to scroll the window
    Component *focusHolder = screen_->focusHolder();
    // clear the window
    for (int i = 0; i < height_; i++) {
      screen->draw(x_, y_ + i, clearLine);
    }
    // set the new row_. if the new focus holder is below our currently
    // visible area we want to increment the row the minimum amount to make it
    // visible, and likewise if it is above, we want to decrement.
    // TODO: These are calculated in scrollNeeded(), see if it would be better
    // to reuse them somehow
    uint8_t yStart = y_;
    uint8_t yEnd = y_ + height_ - 1;
    if (focusHolder->y() > yEnd) {
      // if the component is below our visible window, increment the row count
      // by the difference between the bottom visible row and the y position
      // of the component
      offsetChildren(0, yEnd - focusHolder->y());
    }
    else {
      offsetChildren(0, yStart - focusHolder->y());
    }
    
    lastFocusHolder_ = screen->focusHolder();

    // tell all the children they need to be repainted. we will only paint
    // the ones that are now visible
    repaint();
  }
  for (int i = 0; i < componentCount_; i++) {
    Component *component = components_[i];
    if (component->dirty() && (component->y() >= y_) && (component->y() < y_ + height_)) {
      component->paint(screen);
    }
    else {
      component->clearDirty();
    }
  }
}

////////////////////////////////////////////////////////////////////////////////
// CharSet
////////////////////////////////////////////////////////////////////////////////

int CharSet::indexOf(unsigned char ch) {
  for (int i = 0; i < size(); i++) {
    if (charAt(i) == ch) {
      return i;
    }
  }
  return -1;
}

////////////////////////////////////////////////////////////////////////////////
// RangeCharSet
////////////////////////////////////////////////////////////////////////////////

RangeCharSet::RangeCharSet(int rangeCount, ...) {
  rangeCount_ = (unsigned char) rangeCount;
  ranges_ = (unsigned char *) malloc(sizeof(unsigned char) * rangeCount * 2);
  va_list argp;
	va_start(argp, rangeCount);
	for (int i = 0; i < rangeCount; i++) {
  	ranges_[i * 2] = (unsigned char) va_arg(argp, int);
  	ranges_[i * 2 + 1] = (unsigned char) va_arg(argp, int);
  }
	va_end(argp);
}

RangeCharSet::~RangeCharSet() {
  free(ranges_);
}

int RangeCharSet::charAt(int index) {
  // determine which range the index falls within by iterating the ranges
  // and then use that plus the index to determine the character
  int currentIndex = 0;
  for (int i = 0; i < rangeCount_; i++) {
    if (index >= currentIndex && index <= currentIndex + (ranges_[i * 2 + 1] - ranges_[i * 2])) {
      unsigned char ch = (unsigned char) (ranges_[i * 2] + (index - currentIndex));
      return (int) ch;
    }
    else {
      currentIndex += (ranges_[i * 2 + 1] - ranges_[i * 2]) + 1;
    }
  }
  return -1;
}

unsigned char RangeCharSet::size() {
  unsigned char size = 0;
  for (int i = 0; i < rangeCount_; i++) {
    size += (ranges_[i * 2 + 1] - ranges_[i * 2]) + 1;
  }
  return size;
}

RangeCharSet defaultCharSet(8,
  32, 32,   // space
  65, 90,   // capital letters
  97, 122,  // lowercase letters
  48, 57,   // digits
  33, 47,   // special chars
  58, 64,   // special chars
  91, 96,   // special chars
  123, 126  // special chars
  );
  
RangeCharSet floatingPointCharSet(4,
  32, 32,   // space
  48, 57,   // digits
  46, 46,   // period
  45, 45    // negative
  );