[image file view] add a new version of 'image zoomer'(zoom in/out icons, and a scale menu) (#8059)

frontend/src/components/file-content-view/image.js

@@ -82,7 +82,7 @@ class FileContent extends React.Component {
     }
 
     return (
-      <div className="file-view-content flex-1 image-file-view">
+      <div className="file-view-content flex-1 image-file-view d-flex align-items-center justify-content-center">
         {previousImage && (
           <a href={previousImageUrl} id="img-prev" title={gettext('you can also press ← ')}><span className="sf3-font sf3-font-down rotate-90 d-inline-block"></span></a>
         )}

frontend/src/components/file-view/image-zoomer.js

@@ -1,57 +1,167 @@
 import React, { useState, useCallback } from 'react';
 import PropTypes from 'prop-types';
-import { Button, Input } from 'reactstrap';
-import Icon from '../../components/icon';
+import { Input, Dropdown, DropdownMenu, DropdownToggle, DropdownItem } from 'reactstrap';
+import IconButton from '../../components/icon-button';
+import { gettext } from '../../utils/constants';
 
-import '../../metadata/components/data-process-setter/gallery-slider-setter/index.css';
-
-const SCALE_OPTIONS = [0.25, 0.5, 1, 1.5, 2];
+const SCALE_OPTIONS = [0.15, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4];
 const SCALE_MIN = SCALE_OPTIONS[0];
 const SCALE_MAX = SCALE_OPTIONS[SCALE_OPTIONS.length - 1];
+const SCALE_OPTIONS_2 = [
+  { value: 'page-fit', text: gettext('Page Fit') },
+  { value: 'actual-size', text: gettext('Actual Size') }
+];
 
 const ImageZoomer = ({ setImageScale }) => {
 
   const [curScale, setScale] = useState(1);
+  const [curScaleText, setScaleText] = useState(`${curScale * 100}%`); // for the text shown in the input
+  const [selectedScale, setSelectedScale] = useState(1); // for the scale menu
+  const [isScaleMenuOpen, setScaleMenuOpen] = useState(false);
+
+  const toggleMenu = useCallback(() => {
+    setScaleMenuOpen(!isScaleMenuOpen);
+  }, [isScaleMenuOpen, setScaleMenuOpen]);
 
   const scaleImage = useCallback((scale) => {
     setImageScale(scale);
   }, [setImageScale]);
 
-  const changeScale = useCallback((e) => {
-    const scale = Number(e.target.value);
+  const zoomInOrOut = useCallback((scale) => {
     setScale(scale);
     scaleImage(scale);
+    setScaleText(`${Math.round(scale * 100)}%`); // handle the result of floating point arithmetic
+    if (SCALE_OPTIONS.indexOf(scale) == -1) {
+      setSelectedScale(null);
+    } else {
+      setSelectedScale(scale);
+    }
   }, [scaleImage]);
 
   const zoomIn = useCallback(() => {
-    const scale = SCALE_OPTIONS[SCALE_OPTIONS.indexOf(curScale) + 1];
-    setScale(scale);
-    scaleImage(scale);
-  }, [curScale, scaleImage]);
+    const offset = Math.ceil(curScale) * 0.1; // round up
+    const normalizedScale = Number((curScale + offset).toFixed(2)); // handle the result of floating point arithmetic
+    const scale = Math.min(normalizedScale, SCALE_MAX);
+    zoomInOrOut(scale);
+  }, [curScale, zoomInOrOut]);
 
   const zoomOut = useCallback(() => {
-    const scale = SCALE_OPTIONS[SCALE_OPTIONS.indexOf(curScale) - 1];
+    const offset = Math.ceil(curScale) * 0.1; // round up
+    const normalizedScale = Number((curScale - offset).toFixed(2)); // handle the result of floating point arithmetic
+    const scale = Math.max(normalizedScale, SCALE_MIN);
+    zoomInOrOut(scale);
+  }, [curScale, zoomInOrOut]);
+
+  const scaleImageToPageFit = useCallback(() => {
+    const imageElement = document.getElementById('image-view');
+    const borderWidth = 1;
+    const width = imageElement.clientWidth + borderWidth * 2;
+    const height = imageElement.clientHeight + borderWidth * 2;
+
+    const imageContainer = imageElement.parentNode;
+    const hPadding = 0; // horizontal padding
+    const vPadding = 30; // vertical padding
+    const maxWidth = imageContainer.clientWidth - hPadding * 2;
+    const maxHeight = imageContainer.clientHeight - vPadding * 2;
+
+    const hScale = maxWidth / width;
+    const vScale = maxHeight / height;
+    const scale = Math.min(hScale, vScale);
     setScale(scale);
     scaleImage(scale);
-  }, [curScale, scaleImage]);
+  }, [setScale, scaleImage]);
+
+  const onMenuItemClick = useCallback((value) => {
+    setSelectedScale(value);
+    if (SCALE_OPTIONS.indexOf(value) != -1) {
+      const scale = value;
+      setScale(scale);
+      scaleImage(scale);
+      setScaleText(`${scale * 100}%`);
+    } else {
+      if (value == 'actual-size') {
+        const scale = 1;
+        setScale(scale);
+        scaleImage(scale);
+      } else {
+        // 'page-fit'
+        scaleImageToPageFit();
+      }
+      setScaleText(SCALE_OPTIONS_2.filter(item => item.value == value)[0].text);
+    }
+    setScaleMenuOpen(false);
+  }, [scaleImage, setScaleMenuOpen, scaleImageToPageFit]);
+
+  const onMenuItemKeyDown = useCallback((e, value) => {
+    if (e.key == 'Enter' || e.key == 'Space') {
+      onMenuItemClick(value);
+    }
+  }, [onMenuItemClick]);
 
   return (
-    <div className='metadata-slider-container image-zoomer ml-0'>
-      <Button className="metadata-slider-icon-button" onClick={zoomOut} disabled={curScale == SCALE_MIN}>
-        <Icon symbol='minus_sign' className='metadata-slider-icon' />
-      </Button>
-      <Input
-        type="range"
-        min={SCALE_MIN}
-        max={SCALE_MAX}
-        step="any"
-        value={curScale}
-        onChange={changeScale}
-        className="metadata-slider"
+    <div className='d-flex align-items-center image-zoomer'>
+      <IconButton
+        id="zoom-out-image"
+        icon="minus_sign"
+        text={gettext('Zoom out')}
+        onClick={zoomOut}
+        disabled={curScale == SCALE_MIN}
+      />
+      <Dropdown
+        isOpen={isScaleMenuOpen}
+        toggle={toggleMenu}
+        className="vam"
+        direction='down'
+      >
+        <DropdownToggle
+          tag='div'
+          className="position-relative"
+          data-toggle="dropdown"
+          aria-expanded={isScaleMenuOpen}
+        >
+          <Input id="cur-scale-input" type="text" value={curScaleText} readOnly={true} />
+          <i id="scale-menu-caret" className="sf3-font-down sf3-font"></i>
+        </DropdownToggle>
+        <DropdownMenu id="scale-menu">
+          {SCALE_OPTIONS.map((item, index) => {
+            return (
+              <DropdownItem
+                key={index}
+                className="position-relative pl-5"
+                onClick={() => {onMenuItemClick(item);}}
+                onKeyDown={(e) => {onMenuItemKeyDown(e, item);}}
+              >
+                {selectedScale == item && (
+                  <i className="dropdown-item-tick sf2-icon-tick"></i>
+                )}
+                <span>{`${item * 100}%`}</span>
+              </DropdownItem>
+            );
+          })}
+          {SCALE_OPTIONS_2.map((item, index) => {
+            return (
+              <DropdownItem
+                key={index}
+                className="position-relative pl-5"
+                onClick={() => {onMenuItemClick(item.value);}}
+                onKeyDown={(e) => {onMenuItemKeyDown(e, item.value);}}
+              >
+                {selectedScale == item.value && (
+                  <i className="dropdown-item-tick sf2-icon-tick"></i>
+                )}
+                <span>{item.text}</span>
+              </DropdownItem>
+            );
+          })}
+        </DropdownMenu>
+      </Dropdown>
+      <IconButton
+        id="zoom-in-image"
+        icon="plus_sign"
+        text={gettext('Zoom in')}
+        onClick={zoomIn}
+        disabled={curScale == SCALE_MAX}
       />
-      <Button className="metadata-slider-icon-button" onClick={zoomIn} disabled={curScale == SCALE_MAX}>
-        <Icon symbol='plus_sign' className='metadata-slider-icon' />
-      </Button>
     </div>
   );
 };

frontend/src/css/image-file-view.css

@@ -18,8 +18,6 @@
   border: 1px solid #eee;
   width: auto;
   height: auto;
-  max-width: calc(100% - 4px);
-  max-height: calc(100% - 4px);
   font-size: 0;
   line-height: 0;
 }
@@ -51,6 +49,32 @@
   color: var(--bs-body-color);
 }
 
-.image-zoomer {
-  height: 24px;
+.image-zoomer #zoom-out-image {
+  margin-right: 2px;
+  font-size: 18px; /* the actual icon is smaller than the others */
+}
+
+.image-zoomer #zoom-in-image {
+  margin-left: 2px;
+  font-size: 18px; /* the actual icon is smaller than the others */
+}
+
+.image-zoomer #cur-scale-input {
+  height: 28px;
+  width: 120px;
+  user-select: none;
+}
+
+.image-zoomer #scale-menu {
+  min-width: 120px; /* overwrite css from seahub_react.css */
+  width: 120px;
+}
+
+.image-zoomer #scale-menu-caret {
+  position: absolute;
+  right: 12px;
+  top: 9px;
+  font-size: 9px;
+  line-height: 1;
+  color: #666;
 }