colorSelect.c

This example shows how to use the Color Picker to and two slider bars to select color and size of a matrix of rectangles on screen. It also adds a button to end the execution of the program.

#include <stdio.h>
#include <stdlib.h>

#include <mgsLib.h>
#include <mrmWidgets.h>


#define SCRW    800
#define SCRH    500
#define SIZE    48
#define GAP     2
#define FREE    50



int main() {
    // Handlers for the main graphic elements
    int scr, cp, slh, slv, btn;
    // Variables to control aspect: color, sizes and positions
    int col, width, height, nh, nv;
    // Generic and auxiliar variables.
    int i, j;
    char buffer[100];
    
    // Create the main screen and set the font for its texts
    if ((scr = mgsCreateScreen(SCRW, SCRH, "Selecting colors", MGS_CBLACK, NULL)) < 0)
        exit(EXIT_FAILURE);
    mgsSetFont(scr, 30, MGS_CWHITE, MGS_TRANSPARENT);   
    // Create the color picker widget
    if ((cp = mrmCPInit(0x808080, MGS_CWHITE)) < 0)
        exit(EXIT_FAILURE);
    // Move it and the main window to a suitable place on screen
    mrmCPMove(20, 130);
    mgsMoveScreen(scr, 300, 150);
    // Create the horizontal and vertical sliders and place on top and left sides respectively
    slh = mrmSliderInit(scr, MWG_SLHORIZONTAL, 25, SCRW - 50, 0.0, SIZE, MGS_CGREY, MGS_CRED, 0x000080, 0x202020);
    slv = mrmSliderInit(scr, MWG_SLVERTICAL, 25, SCRH - 50, 0.0, SIZE, MGS_CGREY, MGS_CRED, 0x000080, 0x202020);
    mrmSliderSetPos(slh, 40, 5);
    mrmSliderSetPos(slv, 5, 40);
    // Create the exit button and set its aspect
    btn = mrmButtonInit(scr, 80, 40, NULL, "Exit", MGS_CGREY, 0x202020, MGS_CBLACK);
    mrmButtonSetFont(btn, 26, 0, "Arial", MGS_BOLD);
    mrmButtonSetFontColor(btn, 0x2020E0, MGS_CRED, 0x2020E0);
    mrmButtonSetPos(btn, SCRW - 100, SCRH - 50);
    
    // Calculate the horizontal and vertical number of rectangles
    nh = 1 + (SCRW - SIZE - GAP - 50) / (SIZE + GAP);
    nv = 1 + (SCRH - SIZE - GAP - 50 - FREE) / (SIZE + GAP);

    // Main animation loop: stay until the user presses the button.
    while(mrmButtonGetCounter(btn) == 0) {
        // Call widget loop
        mrmWLoop();
        // Read the height and width of the rectangles from the sliders
        width = mrmSliderGetVal(slh);
        height = mrmSliderGetVal(slv);
        // Get the color from the picker
        col = mrmCPRGB();
        // And prepare the text
        sprintf(buffer, "Width: %d - Height: %d", width, height);
        
        // Clear the screen and start to draw
        mgsClearScreen(scr);
        
        // A small square at the top left corner of  complementary color
        mgsRectangle(scr, 5, 5, 30, 30, ~col & 0xFFFFFF);

        // The matrix of rectangles of the selected color, whose size depends on the sliders
        for(i = 0; i < nh; i++)
            for(j = 0; j < nv; j++)
                mgsRectangle(scr, i * (SIZE + GAP) + 40, j * (SIZE + GAP) + 40, i * (SIZE + GAP) + 40 + width, j * (SIZE + GAP) + 40 + height, col);
        
        // And show the values read with the text
        mgsPutsAligned(scr, MGS_THCENTER | MGS_TVCENTER, 0, SCRH - FREE - 30, SCRW, SCRH, buffer);
        
        // Call to draw all widgets
        mrmWShow();
        
        // And synchronize and update screen to end the animation.
        mgsWaitFrame();
        mgsUpdateScreen(scr);
    }
    
    // Good bye.
    exit(EXIT_SUCCESS);
}