fltk/test/unittest_text.cxx

108 lines
3.7 KiB
C++

//
// Unit tests for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2022 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
// https://www.fltk.org/bugs.php
//
#include "unittests.h"
#include <FL/Fl_Box.H>
#include <FL/Fl_Check_Button.H>
#include <FL/fl_draw.H>
//
// --- fl_text_extents() tests -----------------------------------------------
static void cb_base_bt(Fl_Widget *bt, void*) {
bt->parent()->redraw();
}
//
class TextExtentsTest : public Fl_Group
{
Fl_Check_Button *base_bt;
void DrawTextAndBoxes(const char *txt, int X, int Y) {
int wm = 0, hm = 0, wt = 0, ht = 0;
int dx, dy;
// measure text so we can draw the baseline first
fl_measure(txt, wm, hm, 0);
fl_text_extents(txt, dx, dy, wt, ht);
// Draw a baseline before the boxes
if (base_bt->value()) {
fl_color(FL_BLUE);
fl_line((X - 20), Y, (X + wt + 20), Y);
}
// Then we draw the bounding boxes (fl_measure and fl_text_extents)
// draw fl_measure() typographical bounding box
int desc = fl_descent();
fl_color(FL_RED);
fl_rect(X, Y-hm+desc, wm, hm);
// draw fl_text_extents() glyph bounding box
fl_color(FL_GREEN);
fl_rect(X+dx, Y+dy, wt, ht);
// Then we draw the text to show how it fits inside each of the two boxes
fl_color(FL_BLACK);
fl_draw(txt, X, Y);
}
public:
static Fl_Widget *create() {
return new TextExtentsTest(TESTAREA_X, TESTAREA_Y, TESTAREA_W, TESTAREA_H);
}
TextExtentsTest(int x, int y, int w, int h) : Fl_Group(x, y, w, h) {
base_bt = new Fl_Check_Button(x + w - 150, 50, 130, 20, "Show Baseline");
base_bt->box(FL_FLAT_BOX);
base_bt->down_box(FL_DOWN_BOX);
base_bt->callback(cb_base_bt);
Fl_Box *dummy = new Fl_Box ((x + w - 4), (y + h - 4), 2, 2);
resizable(dummy);
end();
}
void draw(void) {
int x0 = x(); // origin is current window position for Fl_Box
int y0 = y();
int w0 = w();
int h0 = h();
fl_push_clip(x0, y0, w0, h0); // reset local clipping
{
// set the background colour - slightly off-white to enhance the green bounding box
fl_color(fl_gray_ramp(FL_NUM_GRAY - 3));
fl_rectf(x0, y0, w0, h0);
Fl_Group::draw();
fl_font(FL_HELVETICA, 30);
int xx = x0+55;
int yy = y0+40;
DrawTextAndBoxes("!abcdeABCDE\"#A", xx, yy); yy += 50; // mixed string
DrawTextAndBoxes("oacs", xx, yy); xx += 100; // small glyphs
DrawTextAndBoxes("qjgIPT", xx, yy); yy += 50; xx -= 100; // glyphs with descenders
DrawTextAndBoxes("````````", xx, yy); yy += 50; // high small glyphs
DrawTextAndBoxes("--------", xx, yy); yy += 50; // mid small glyphs
DrawTextAndBoxes("________", xx, yy); yy += 50; // low small glyphs
fl_font(FL_HELVETICA, 14);
fl_color(FL_RED); fl_draw("fl_measure bounding box in RED", xx, yy); yy += 20;
fl_color(FL_GREEN); fl_draw("fl_text_extents bounding box in GREEN", xx, yy);
fl_color(FL_BLACK);
xx = x0 + 10; yy += 30;
fl_draw("NOTE: On systems with text anti-aliasing (e.g. macOS Quartz)", xx, yy);
w0 = h0 = 0; fl_measure("NOTE: ", w0, h0, 0);
xx += w0; yy += h0;
fl_draw("text may leak slightly outside the fl_text_extents()", xx, yy);
}
fl_pop_clip(); // remove the local clip
}
};
UnitTest textExtents(kTestText, "Rendering text", TextExtentsTest::create);