Karabiner config for using only mouse for switching between spaces and mission control (virtual modifiers)

mouse.json

  {
      "description": "Maps button 5 and 4 as modifiers for button 1 and 2 to switch spaces and desktops",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "pointing_button": "button4",
            "modifiers": {
              "mandatory": [],
              "optional": [
                "any"
              ]
            }
          },
          "to_if_alone": [
            {
              "pointing_button": "button4"
            }
          ],
          "to": [
            {
              "set_variable": {
                "name": "button4_modifier",
                "value": 1
              }
            }
          ],
          "to_after_key_up": [
            {
              "set_variable": {
                "name": "button4_modifier",
                "value": 0
              }
            }
          ]
        },
        {
          "type": "basic",
          "from": {
            "pointing_button": "button5",
            "modifiers": {
              "mandatory": [],
              "optional": [
                "any"
              ]
            }
          },
          "to_if_alone": [
            {
              "pointing_button": "button5"
            }
          ],
          "to": [
            {
              "set_variable": {
                "name": "button5_modifier",
                "value": 1
              }
            }
          ],
          "to_after_key_up": [
            {
              "set_variable": {
                "name": "button5_modifier",
                "value": 0
              }
            }
          ]
        },
        {
          "type": "basic",
          "from": {
            "pointing_button": "button1",
            "modifiers": {
              "mandatory": [],
              "optional": [
                "any"
              ]
            }
          },
          "to_if_alone": [
            {
              "pointing_button": "button1"
            }
          ],
          "to": [
            {
              "key_code": "left_arrow",
              "modifiers": "left_control"
            }
          ],
          "conditions": [
            {
              "type": "variable_if",
              "name": "button4_modifier",
              "value": 1
            }
          ]
        },
        {
          "type": "basic",
          "from": {
            "pointing_button": "button2",
            "modifiers": {
              "mandatory": [],
              "optional": [
                "any"
              ]
            }
          },
          "to_if_alone": [
            {
              "pointing_button": "button2"
            }
          ],
          "to": [
            {
              "key_code": "right_arrow",
              "modifiers": "left_control"
            }
          ],
          "conditions": [
            {
              "type": "variable_if",
              "name": "button4_modifier",
              "value": 1
            }
          ]
        },
        {
          "type": "basic",
          "from": {
            "pointing_button": "button1",
            "modifiers": {
              "mandatory": [],
              "optional": [
                "any"
              ]
            }
          },
          "to_if_alone": [
            {
              "pointing_button": "button1"
            }
          ],
          "to": [
            {
              "key_code": "up_arrow",
              "modifiers": "left_control"
            }
          ],
          "conditions": [
            {
              "type": "variable_if",
              "name": "button5_modifier",
              "value": 1
            }
          ]
        },
        {
          "type": "basic",
          "from": {
            "pointing_button": "button2",
            "modifiers": {
              "mandatory": [],
              "optional": [
                "any"
              ]
            }
          },
          "to_if_alone": [
            {
              "pointing_button": "button2"
            }
          ],
          "to": [
            {
              "key_code": "down_arrow",
              "modifiers": "left_control"
            }
          ],
          "conditions": [
            {
              "type": "variable_if",
              "name": "button5_modifier",
              "value": 1
            }
          ]
        }
      ]
    }