How can I get the width of a character in a specific font?

Ok: Text width solution works:

For any one interested, here my solution to calculate the Cursor position for the current buffer position:

int CustomKeyboard::calcCursorPosition()

{

   int n=0, nPos, nCursorPos=0;

   // get font from assets

   Font* font = FontManager::getFont(Typography::CALIBRIMEDIUM);

   nPos = keyboard.getBufferPosition();

   for (n = 0; n < nPos; n++)

   {

       nCursorPos+= font->getCharWidth(buffer[n]);

   }

   return nCursorPos;

}

Ok, and now I got the insert functionality working with following steps:

1)

Save Text of keyboard buffer to a copy buffer at startup and every time a character is inserted:

Unicode::strncpy(bufSav, buffer, BUFFER_SIZE);

2)

Adapt keyPressedhandler:

void CustomKeyboard::keyPressedhandler(Unicode::UnicodeChar keyChar)

{

   uint16_t pos = keyboard.getBufferPosition();

   int n, nSize,nSizeOld;

   nSize = Unicode::strlen(buffer);

   nSizeOld = Unicode::strlen(bufSav);

   if ((nSizeOld >= nSize) &&  (nSizeOld > 0)) 

   {

       if (bClickedSpecialKey != true)   // not Backspace/Mode/Shift?

       {

            // Restore remaining text from copy

           for (n = pos; n < BUFFER_SIZE; n++)

           {

               buffer[n] = bufSav[n-1];

           }

       }

   }

   bClickedSpecialKey = false;

   // Save current buffer for Insert-Handling

   Unicode::strncpy(bufSav, buffer, BUFFER_SIZE);

   // After the first keypress, the keyboard will shift to lowercase.

   if (firstCharacterEntry && keyChar != 0)

   {

       firstCharacterEntry = false;

       uppercaseKeys = false;

       setKeyMappingList();

   }

   setCaret(); // Cursor at current position

}

This is very helpful. I'm also going to need a full keyboard for my project. I was going to write my own as I want to be able to allow users to edit better. Only allowing them to BS over the last character will not cut it for my project.

I was going to just write my own keyboard from scratch, but it looks like you have enhanced the current custom keyboard object.

Thanks for posting this.

Ok, finally I have the time to provide the last step for setting the cursor to any place within the string by clicking in the text area:

1) Forward the handleClickEvent to the CustomKeyboard form the view.

2) Handle Click Event in the CustomKeyboard:

void CustomKeyboard::handleClickEvent(const ClickEvent& evt)

{

   unsigned int x = evt.getX();

   unsigned int y = evt.getY();

   // in case clicked into text field area:

   if ((x >= TEXT_POS_X) && (x <= (TEXT_POS_X + TEXT_POS_WIDTH)) &&

       (y >= TEXT_POS_Y) && (y <= (TEXT_POS_Y + TEXT_POS_HEIGHT)))

   {

       x -= TEXT_POS_X;

   // find closest Position of click event

       m_position = findPosition(x);

       //This find the end of buffer so that the caret will not appear at a weird place

       if (m_position > BUFFER_SIZE)

       {

           m_position = BUFFER_SIZE;

       }

       keyboard.setBufferPosition(m_position);

       setCaret();

   }

}

uint16_t CustomKeyboard::findPosition(int x)

{

   int nSize, i, nTextPos=0;

   nSize = Unicode::strlen(buffer);

   for (nTextPos = 0; nTextPos <= nSize; nTextPos++)

   {

       i = calcCursorPosition(nTextPos);  

       if (i >= x)    // Beyond clicked Position

       {

           // Cursor would be set after the character which is on the right side of the click position

           if (nTextPos > 0)

               nTextPos--;    // Therefore: set to one position on the left

           return (uint16_t)nTextPos;

        }

   return (uint16_t)nTextPos;

}