Modify checkboxes so that they can be indeterminate

To add the third state, we create our own checkboxes using font awesome
icons.

scm-ui/ui-components/src/forms/Checkbox.stories.tsx

@@ -35,6 +35,7 @@ storiesOf("Forms|Checkbox", module)
     <Spacing>
       <Checkbox label="Not checked" checked={false} />
       <Checkbox label="Checked" checked={true} />
+      <Checkbox label="Indeterminate" checked={true} indeterminate={true} />
     </Spacing>
   ))
   .add("Disabled", () => (

scm-ui/ui-components/src/forms/Checkbox.tsx

@@ -24,11 +24,13 @@
 import React, { ChangeEvent } from "react";
 import { Help } from "../index";
 import LabelWithHelpIcon from "./LabelWithHelpIcon";
+import TriStateCheckbox from "./TriStateCheckbox";
 
 type Props = {
   label?: string;
   onChange?: (value: boolean, name?: string) => void;
   checked: boolean;
+  indeterminate?: boolean;
   name?: string;
   title?: string;
   disabled?: boolean;
@@ -36,9 +38,9 @@ type Props = {
 };
 
 export default class Checkbox extends React.Component<Props> {
-  onCheckboxChange = (event: ChangeEvent<HTMLInputElement>) => {
+  onCheckboxChange = () => {
     if (this.props.onChange) {
-      this.props.onChange(event.target.checked, this.props.name);
+      this.props.onChange(!this.props.checked, this.props.name);
     }
   };
 
@@ -57,18 +59,19 @@ export default class Checkbox extends React.Component<Props> {
   };
 
   render() {
-    const { label, checked, disabled } = this.props;
+    const { label, checked, indeterminate, disabled } = this.props;
     return (
       <div className="field">
         {this.renderLabelWithHelp()}
-        <div className="control">
+        <div className="control" onClick={this.onCheckboxChange}>
           {/*
             we have to ignore the next line,
             because jsx label does not the custom disabled attribute
             but bulma does.
             // @ts-ignore */}
           <label className="checkbox" disabled={disabled}>
-            <input type="checkbox" checked={checked} onChange={this.onCheckboxChange} disabled={disabled} /> {label}
+            <TriStateCheckbox checked={checked} indeterminate={indeterminate} disabled={disabled} />
+            {label}
             {this.renderHelp()}
           </label>
         </div>

scm-ui/ui-components/src/forms/TriStateCheckbox.tsx

@@ -0,0 +1,72 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+import React, { FC } from "react";
+import Icon from "../Icon";
+
+type Props = {
+  onChange?: (value: boolean) => void;
+  checked: boolean;
+  indeterminate?: boolean;
+  disabled?: boolean;
+  label?: string;
+};
+
+const TriStateCheckbox: FC<Props> = ({ onChange, checked, indeterminate, disabled, label }) => {
+  const onCheckboxChange = () => {
+    if (onChange) {
+      console.log("clickediclick");
+      onChange(!checked);
+    }
+  };
+
+  let icon;
+  if (indeterminate) {
+    icon = "minus-square";
+  } else if (checked) {
+    icon = "check-square";
+  } else {
+    icon = "square";
+  }
+
+  let className;
+  if (!checked || indeterminate) {
+    className = "far";
+  } else {
+    className = "fa";
+  }
+
+  let color;
+  if (disabled) {
+    color = "grey-light";
+  } else if (checked || indeterminate) {
+    color = "blue";
+  } else {
+    color = "black";
+  }
+
+  return <><Icon iconStyle={"is-outlined"} name={icon} className={className} color={color} />{" "}
+  {label}</>;
+};
+
+export default TriStateCheckbox;