The for-loop will tell you all information you need, the printable ASCII characters and its index position For example:If i run the for-loop in my PC it will print something like this:
30 �
31 �
32
33 !
34 "
35 #
36 $
37 %
........
122 z
123 {
124 |
125 }
126 ~
127
128 �
129 �From the output, we can easily now detect all of printable chars and its indices which is clearly the printable chars start from index 32 upto 127. now, we need to add this boundary check to SFML event-loop:
//if (event.text.unicode >= 32 && event.text.unicode <= 127)
if (std::isprint(event.text.unicode)) // thanks to Laurent
input_text += event.text.unicode;
Don't worry about if user press BackSpace or Return/Enter keys, sf::Text will take care for these inputs internally, just supply the string to sf::Text::setString with escape char in event-loop:
if (event.key.code == sf::Keyboard::BackSpace) {
if (!input_text.empty())
input_text.pop_back();// as Laurent pointed out
//input_text.erase(--input_text.end());
}
if (event.key.code == sf::Keyboard::Return){
input_text += '\n';
}
That's it, we have accomplished a minimal text editor.
I added a simple blinking effect to “cursor”. It was a part of my early demos when I was working out with the SFML library.
Here the complete source source:
#include <SFML/Graphics.hpp>
#include <locale>
int main()
{
sf::RenderWindow window({ 640 ,480 }, "test");
std::string input_text;
sf::Font font;
font.loadFromFile("resources/font.ttf");
sf::Text text("", font);
sf::Clock clock;
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed)
window.close();
else if (event.type == sf::Event::TextEntered) {
if (std::isprint(event.text.unicode))
input_text += event.text.unicode;
}
else if (event.type == sf::Event::KeyPressed) {
if (event.key.code == sf::Keyboard::BackSpace) {
if (!input_text.empty())
input_text.pop_back();
}
if (event.key.code == sf::Keyboard::Return) {
input_text += '\n';
}
}
}
static sf::Time text_effect_time;
static bool show_cursor;
text_effect_time += clock.restart();
if (text_effect_time >= sf::seconds(0.5f))
{
show_cursor = !show_cursor;
text_effect_time = sf::Time::Zero;
}
text.setString(input_text + (show_cursor ? '_' : ' '));
window.clear();
window.draw(text);
window.display();
}
}
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