Macro Mod script for minecraft to be used in conjunction with minebot (https://github.com/michaelzangl/minebot). Checks if hotbar contains Picks/shovels/dirt, and if not, refills the hotbar from the inventory. Could be edited to use without minebot.

gistfile1.txt

&pick = "stone_pickaxe";
&shovel = "stone_shovel";
&pillar = "dirt";

IF(automine);
    LOG("Automine Disabled");
    ECHO("/minebot stop");
    UNSET(automine);
ELSE;
    LOG("Automine Enabled");
    LOG("Enabling minebot");
    WAIT(200ms);
    ECHO("/minebuild clear")
    SET(automine);
    DO;
    IF((%ITEM% != %&pick%) && (%ITEM% != %&shovel%) && (%ITEM% != %&pillar%));
        LOG("Not holding pick/shovel/" %&pillar%);
        #c=1;
        #pc = 5;
        #sc = 2;
        FOR(#f,0,6);
            &hi = GETSLOTITEM(%#c%);
            IF(%#c% < 6);
                //LOG(%&hi% at %#c%);
                IF(%&hi% != %&pick%);
                    #pc = #pc - 1;                   
                ENDIF;
            ELSE;
                //LOG(%&hi% at %#c%);                
                IF(%&hi% != %&shovel%);
                    #sc = #sc - 1;                    
                ENDIF;
            ENDIF;
            #c = #c + 1;
        NEXT;
        LOG("Number of Picks = " %#pc%);
        LOG("Number of Shovels = " %#sc%);
        IF((%#pc%   = 0) || (%#sc% = 0));
            LOG("Need to refill hotbar");
            ECHO("/minebot stop");
            GUI(inventory);
            //WAIT(500ms);
            #hs = 36;
            FOR(#for,0,6);
                WAIT(200ms);
                &hi = GETSLOTITEM(%#hs%);
                IF(%#hs% < 41);
                    IF(%&hi% != %&pick%);
                        GETSLOT(%&pick%,#is,9);
                        &ii = GETSLOTITEM(%#is%);
                        IF((%#is% <36)&&(%#is% != -1));
                            SLOTCLICK(%#is%,2,false);
                            SLOTCLICK(%#hs%,1,false);
                            SLOTCLICK(%#is%,1,false);
                        ELSE;
                            LOG("No Picks found in inventory, might be time to refill!");
                        ENDIF;
                    ENDIF;
                ELSE;
                    IF(%&hi != %&shovel%);
                        GETSLOT(%&shovel%,#is,9);
                        &ii = GETSLOTITEM(%#is%);
                        IF((%#is% <36) && (%#is% != -1));
                            SLOTCLICK(%#is%,2,false);
                            SLOTCLICK(%#hs%,1,false);
                            SLOTCLICK(%#is%,1,false);
                        ELSE;
                            LOG("No Shovels Found in inventory, might be time to refill!");
                        ENDIF;
                    ENDIF;                        
                ENDIF;
                #hs = #hs + 1;
            NEXT;
            GUI();
            //Run a final check on the hotbar, in case there was nothing in the inventory
            #c = 1;
            #pc = 5;
            #sc = 2;
            FOR(#f,0,6);
                &hi = GETSLOTITEM(%#c%);
                IF(%#c% < 6);                    
                    IF(%&hi% != %&pick%);
                        #pc = #pc - 1;                   
                    ENDIF;
                ELSE;                                   
                    IF(%&hi% != %&shovel%);                       
                        #sc = #sc - 1;                    
                    ENDIF;
                ENDIF;
                #c = #c + 1;
            NEXT;
            IF((%#pc% = 0) || (%#sc% = 0));
                LOG("You have run out of either shovels or picks");
                LOG("Stopping operations");
                LOG("Maybe one day I will get my own picks");
                LOG("If Adam can be bothered");
                UNSET(automine);
            ELSE;
                WAIT(1000ms);   
                LOG("Starting Minebot");
                ECHO("/minebuild clear");
            ENDIF;
        ELSE;
            LOG("No need to refill yet");
        ENDIF;
        IF(%ITEM% != "dirt");
            //KEY(use);
        ENDIF;
    ENDIF;
    WHILE(automine);
    ECHO("/minebot stop");
ENDIF;

As a note, I don't think the scripting language is real Java. But it highlights nicely