mirror of
https://github.com/thelounge/thelounge.git
synced 2024-05-02 14:42:53 +02:00
406 lines
11 KiB
Vue
406 lines
11 KiB
Vue
<template>
|
|
<div
|
|
id="image-viewer"
|
|
ref="viewer"
|
|
:class="{opened: link !== null}"
|
|
@wheel="onMouseWheel"
|
|
@touchstart.passive="onTouchStart"
|
|
@click="onClick"
|
|
>
|
|
<template v-if="link !== null">
|
|
<button class="close-btn" aria-label="Close"></button>
|
|
|
|
<button
|
|
v-if="previousImage"
|
|
class="previous-image-btn"
|
|
aria-label="Previous image"
|
|
@click.stop="previous"
|
|
></button>
|
|
<button
|
|
v-if="nextImage"
|
|
class="next-image-btn"
|
|
aria-label="Next image"
|
|
@click.stop="next"
|
|
></button>
|
|
|
|
<a class="open-btn" :href="link.link" target="_blank" rel="noopener"></a>
|
|
|
|
<img
|
|
ref="image"
|
|
:src="link.thumb"
|
|
alt=""
|
|
:style="computeImageStyles"
|
|
@load="onImageLoad"
|
|
@mousedown="onImageMouseDown"
|
|
@touchstart.passive="onImageTouchStart"
|
|
/>
|
|
</template>
|
|
</div>
|
|
</template>
|
|
|
|
<script>
|
|
import Mousetrap from "mousetrap";
|
|
import eventbus from "../js/eventbus";
|
|
|
|
export default {
|
|
name: "ImageViewer",
|
|
data() {
|
|
return {
|
|
link: null,
|
|
previousImage: null,
|
|
nextImage: null,
|
|
channel: null,
|
|
|
|
position: {
|
|
x: 0,
|
|
y: 0,
|
|
},
|
|
transform: {
|
|
x: 0,
|
|
y: 0,
|
|
scale: 0,
|
|
},
|
|
};
|
|
},
|
|
computed: {
|
|
computeImageStyles() {
|
|
// Sub pixels may cause the image to blur in certain browsers
|
|
// round it down to prevent that
|
|
const transformX = Math.floor(this.transform.x);
|
|
const transformY = Math.floor(this.transform.y);
|
|
|
|
return {
|
|
left: `${this.position.x}px`,
|
|
top: `${this.position.y}px`,
|
|
transform: `translate3d(${transformX}px, ${transformY}px, 0) scale3d(${this.transform.scale}, ${this.transform.scale}, 1)`,
|
|
};
|
|
},
|
|
},
|
|
watch: {
|
|
link(newLink, oldLink) {
|
|
// TODO: history.pushState
|
|
if (newLink === null) {
|
|
eventbus.off("escapekey", this.closeViewer);
|
|
eventbus.off("resize", this.correctPosition);
|
|
Mousetrap.unbind("left", this.previous);
|
|
Mousetrap.unbind("right", this.next);
|
|
return;
|
|
}
|
|
|
|
this.setPrevNextImages();
|
|
|
|
if (!oldLink) {
|
|
eventbus.on("escapekey", this.closeViewer);
|
|
eventbus.on("resize", this.correctPosition);
|
|
Mousetrap.bind("left", this.previous);
|
|
Mousetrap.bind("right", this.next);
|
|
}
|
|
},
|
|
},
|
|
methods: {
|
|
closeViewer() {
|
|
if (this.link === null) {
|
|
return;
|
|
}
|
|
|
|
this.channel = null;
|
|
this.previousImage = null;
|
|
this.nextImage = null;
|
|
this.link = null;
|
|
},
|
|
setPrevNextImages() {
|
|
if (!this.channel) {
|
|
return null;
|
|
}
|
|
|
|
const links = this.channel.messages
|
|
.map((msg) => msg.previews)
|
|
.flat()
|
|
.filter((preview) => preview.thumb);
|
|
|
|
const currentIndex = links.indexOf(this.link);
|
|
|
|
this.previousImage = links[currentIndex - 1] || null;
|
|
this.nextImage = links[currentIndex + 1] || null;
|
|
},
|
|
previous() {
|
|
if (this.previousImage) {
|
|
this.link = this.previousImage;
|
|
}
|
|
},
|
|
next() {
|
|
if (this.nextImage) {
|
|
this.link = this.nextImage;
|
|
}
|
|
},
|
|
onImageLoad() {
|
|
this.prepareImage();
|
|
},
|
|
prepareImage() {
|
|
const viewer = this.$refs.viewer;
|
|
const image = this.$refs.image;
|
|
const width = viewer.offsetWidth;
|
|
const height = viewer.offsetHeight;
|
|
const scale = Math.min(1, width / image.width, height / image.height);
|
|
|
|
this.position.x = Math.floor(-image.naturalWidth / 2);
|
|
this.position.y = Math.floor(-image.naturalHeight / 2);
|
|
this.transform.scale = Math.max(scale, 0.1);
|
|
this.transform.x = width / 2;
|
|
this.transform.y = height / 2;
|
|
},
|
|
calculateZoomShift(newScale, x, y, oldScale) {
|
|
const imageWidth = this.$refs.image.width;
|
|
const centerX = this.$refs.viewer.offsetWidth / 2;
|
|
const centerY = this.$refs.viewer.offsetHeight / 2;
|
|
|
|
return {
|
|
x:
|
|
centerX -
|
|
((centerX - (y - (imageWidth * x) / 2)) / x) * newScale +
|
|
(imageWidth * newScale) / 2,
|
|
y:
|
|
centerY -
|
|
((centerY - (oldScale - (imageWidth * x) / 2)) / x) * newScale +
|
|
(imageWidth * newScale) / 2,
|
|
};
|
|
},
|
|
correctPosition() {
|
|
const image = this.$refs.image;
|
|
const widthScaled = image.width * this.transform.scale;
|
|
const heightScaled = image.height * this.transform.scale;
|
|
const containerWidth = this.$refs.viewer.offsetWidth;
|
|
const containerHeight = this.$refs.viewer.offsetHeight;
|
|
|
|
if (widthScaled < containerWidth) {
|
|
this.transform.x = containerWidth / 2;
|
|
} else if (this.transform.x - widthScaled / 2 > 0) {
|
|
this.transform.x = widthScaled / 2;
|
|
} else if (this.transform.x + widthScaled / 2 < containerWidth) {
|
|
this.transform.x = containerWidth - widthScaled / 2;
|
|
}
|
|
|
|
if (heightScaled < containerHeight) {
|
|
this.transform.y = containerHeight / 2;
|
|
} else if (this.transform.y - heightScaled / 2 > 0) {
|
|
this.transform.y = heightScaled / 2;
|
|
} else if (this.transform.y + heightScaled / 2 < containerHeight) {
|
|
this.transform.y = containerHeight - heightScaled / 2;
|
|
}
|
|
},
|
|
// Reduce multiple touch points into a single x/y/scale
|
|
reduceTouches(touches) {
|
|
let totalX = 0;
|
|
let totalY = 0;
|
|
let totalScale = 0;
|
|
|
|
for (let i = 0; i < touches.length; i++) {
|
|
const x = touches[i].clientX;
|
|
const y = touches[i].clientY;
|
|
|
|
totalX += x;
|
|
totalY += y;
|
|
|
|
for (let i2 = 0; i2 < touches.length; i2++) {
|
|
if (i !== i2) {
|
|
const x2 = touches[i2].clientX;
|
|
const y2 = touches[i2].clientY;
|
|
totalScale += Math.sqrt((x - x2) * (x - x2) + (y - y2) * (y - y2));
|
|
}
|
|
}
|
|
}
|
|
|
|
if (totalScale === 0) {
|
|
totalScale = 1;
|
|
}
|
|
|
|
return {
|
|
x: totalX / touches.length,
|
|
y: totalY / touches.length,
|
|
scale: totalScale / touches.length,
|
|
};
|
|
},
|
|
onTouchStart(e) {
|
|
// prevent sidebar touchstart event, we don't want to interact with sidebar while in image viewer
|
|
e.stopImmediatePropagation();
|
|
},
|
|
// Touch image manipulation:
|
|
// 1. Move around by dragging it with one finger
|
|
// 2. Change image scale by using two fingers
|
|
onImageTouchStart(e) {
|
|
const image = this.$refs.image;
|
|
let touch = this.reduceTouches(e.touches);
|
|
let currentTouches = e.touches;
|
|
let touchEndFingers = 0;
|
|
|
|
const currentTransform = {
|
|
x: touch.x,
|
|
y: touch.y,
|
|
scale: touch.scale,
|
|
};
|
|
|
|
const startTransform = {
|
|
x: this.transform.x,
|
|
y: this.transform.y,
|
|
scale: this.transform.scale,
|
|
};
|
|
|
|
const touchMove = (moveEvent) => {
|
|
touch = this.reduceTouches(moveEvent.touches);
|
|
|
|
if (currentTouches.length !== moveEvent.touches.length) {
|
|
currentTransform.x = touch.x;
|
|
currentTransform.y = touch.y;
|
|
currentTransform.scale = touch.scale;
|
|
startTransform.x = this.transform.x;
|
|
startTransform.y = this.transform.y;
|
|
startTransform.scale = this.transform.scale;
|
|
}
|
|
|
|
const deltaX = touch.x - currentTransform.x;
|
|
const deltaY = touch.y - currentTransform.y;
|
|
const deltaScale = touch.scale / currentTransform.scale;
|
|
currentTouches = moveEvent.touches;
|
|
touchEndFingers = 0;
|
|
|
|
const newScale = Math.min(3, Math.max(0.1, startTransform.scale * deltaScale));
|
|
const fixedPosition = this.calculateZoomShift(
|
|
newScale,
|
|
startTransform.scale,
|
|
startTransform.x,
|
|
startTransform.y
|
|
);
|
|
|
|
this.transform.x = fixedPosition.x + deltaX;
|
|
this.transform.y = fixedPosition.y + deltaY;
|
|
this.transform.scale = newScale;
|
|
this.correctPosition();
|
|
};
|
|
|
|
const touchEnd = (endEvent) => {
|
|
const changedTouches = endEvent.changedTouches.length;
|
|
|
|
if (currentTouches.length > changedTouches + touchEndFingers) {
|
|
touchEndFingers += changedTouches;
|
|
return;
|
|
}
|
|
|
|
// todo: this is swipe to close, but it's not working very well due to unfinished delta calculation
|
|
/* if (
|
|
this.transform.scale <= 1 &&
|
|
endEvent.changedTouches[0].clientY - startTransform.y <= -70
|
|
) {
|
|
return this.closeViewer();
|
|
}*/
|
|
|
|
this.correctPosition();
|
|
|
|
image.removeEventListener("touchmove", touchMove, {passive: true});
|
|
image.removeEventListener("touchend", touchEnd, {passive: true});
|
|
};
|
|
|
|
image.addEventListener("touchmove", touchMove, {passive: true});
|
|
image.addEventListener("touchend", touchEnd, {passive: true});
|
|
},
|
|
// Image mouse manipulation:
|
|
// 1. Mouse wheel scrolling will zoom in and out
|
|
// 2. If image is zoomed in, simply dragging it will move it around
|
|
onImageMouseDown(e) {
|
|
// todo: ignore if in touch event currently?
|
|
// only left mouse
|
|
if (e.which !== 1) {
|
|
return;
|
|
}
|
|
|
|
e.stopPropagation();
|
|
e.preventDefault();
|
|
|
|
const viewer = this.$refs.viewer;
|
|
const image = this.$refs.image;
|
|
|
|
const startX = e.clientX;
|
|
const startY = e.clientY;
|
|
const startTransformX = this.transform.x;
|
|
const startTransformY = this.transform.y;
|
|
const widthScaled = image.width * this.transform.scale;
|
|
const heightScaled = image.height * this.transform.scale;
|
|
const containerWidth = viewer.offsetWidth;
|
|
const containerHeight = viewer.offsetHeight;
|
|
const centerX = this.transform.x - widthScaled / 2;
|
|
const centerY = this.transform.y - heightScaled / 2;
|
|
let movedDistance = 0;
|
|
|
|
const mouseMove = (moveEvent) => {
|
|
moveEvent.stopPropagation();
|
|
moveEvent.preventDefault();
|
|
|
|
const newX = moveEvent.clientX - startX;
|
|
const newY = moveEvent.clientY - startY;
|
|
|
|
movedDistance = Math.max(movedDistance, Math.abs(newX), Math.abs(newY));
|
|
|
|
if (centerX < 0 || widthScaled + centerX > containerWidth) {
|
|
this.transform.x = startTransformX + newX;
|
|
}
|
|
|
|
if (centerY < 0 || heightScaled + centerY > containerHeight) {
|
|
this.transform.y = startTransformY + newY;
|
|
}
|
|
|
|
this.correctPosition();
|
|
};
|
|
|
|
const mouseUp = (upEvent) => {
|
|
this.correctPosition();
|
|
|
|
if (movedDistance < 2 && upEvent.button === 0) {
|
|
this.closeViewer();
|
|
}
|
|
|
|
image.removeEventListener("mousemove", mouseMove);
|
|
image.removeEventListener("mouseup", mouseUp);
|
|
};
|
|
|
|
image.addEventListener("mousemove", mouseMove);
|
|
image.addEventListener("mouseup", mouseUp);
|
|
},
|
|
// If image is zoomed in, holding ctrl while scrolling will move the image up and down
|
|
onMouseWheel(e) {
|
|
// if image viewer is closing (css animation), you can still trigger mousewheel
|
|
// TODO: Figure out a better fix for this
|
|
if (this.link === null) {
|
|
return;
|
|
}
|
|
|
|
e.preventDefault(); // TODO: Can this be passive?
|
|
|
|
if (e.ctrlKey) {
|
|
this.transform.y += e.deltaY;
|
|
} else {
|
|
const delta = e.deltaY > 0 ? 0.1 : -0.1;
|
|
const newScale = Math.min(3, Math.max(0.1, this.transform.scale + delta));
|
|
const fixedPosition = this.calculateZoomShift(
|
|
newScale,
|
|
this.transform.scale,
|
|
this.transform.x,
|
|
this.transform.y
|
|
);
|
|
this.transform.scale = newScale;
|
|
this.transform.x = fixedPosition.x;
|
|
this.transform.y = fixedPosition.y;
|
|
}
|
|
|
|
this.correctPosition();
|
|
},
|
|
onClick(e) {
|
|
// If click triggers on the image, ignore it
|
|
if (e.target === this.$refs.image) {
|
|
return;
|
|
}
|
|
|
|
this.closeViewer();
|
|
},
|
|
},
|
|
};
|
|
</script>
|