mirror of
https://github.com/mozilla/pdf.js.git
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Fix issues in text selection
- PR #13257 fixed a lot of issues but not all and this patch aims to fix almost all remaining issues. - the idea in this new patch is to compare position of new glyph with the last position where a glyph has been drawn; - no space are "drawn": it just moves the cursor but they aren't added in the chunk; - so this way a space followed by a cursor move can be treated as only one space: it helps to merge all spaces into one. - to make difference between real spaces and tracking ones, we used a factor of the space width (from the font) - it was a pretty good idea in general but it fails with some fonts where space was too big: - in Poppler, they're using a factor of the font size: this is an excellent idea (<= 0.1 * fontSize implies tracking space).
This commit is contained in:
Calixte Denizet
parent
f5b79be0b7
commit
61d1063276
10 changed files with 361 additions and 143 deletions
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@ -2169,6 +2169,8 @@ class PartialEvaluator {
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stateManager = stateManager || new StateManager(new TextState());
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const WhitespaceRegexp = /\s/g;
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const DiacriticRegExp = new RegExp("^\\p{Mn}$", "u");
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const NormalizedUnicodes = getNormalizedUnicodes();
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const textContent = {
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items: [],
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@ -2182,34 +2184,37 @@ class PartialEvaluator {
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width: 0,
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height: 0,
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vertical: false,
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lastCharSize: 0,
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prevTransform: null,
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textAdvanceScale: 0,
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spaceWidth: 0,
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spaceInFlowMin: 0,
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spaceInFlowMax: 0,
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trackingSpaceMin: Infinity,
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negativeSpaceMax: -Infinity,
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transform: null,
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fontName: null,
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hasEOL: false,
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isLastCharWhiteSpace: false,
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};
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// Used in addFakeSpaces.
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// wsw stands for whitespace width.
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// A white <= wsw * TRACKING_SPACE_FACTOR is a tracking space
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// A white <= fontSize * TRACKING_SPACE_FACTOR is a tracking space
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// so it doesn't count as a space.
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const TRACKING_SPACE_FACTOR = 0.3;
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const TRACKING_SPACE_FACTOR = 0.1;
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// A white with a width in [wsw * MIN_FACTOR; wsw * MAX_FACTOR]
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// A negative white < fontSize * NEGATIVE_SPACE_FACTOR induces
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// a break (a new chunk of text is created).
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// It doesn't change anything when the text is copied but
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// it improves potential mismatch between text layer and canvas.
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const NEGATIVE_SPACE_FACTOR = -0.2;
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// A white with a width in [fontSize * MIN_FACTOR; fontSize * MAX_FACTOR]
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// is a space which will be inserted in the current flow of words.
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// If the width is outside of this range then the flow is broken
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// (which means a new span in the text layer).
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// It's useful to adjust the best as possible the span in the layer
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// to what is displayed in the canvas.
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const SPACE_IN_FLOW_MIN_FACTOR = 0.3;
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const SPACE_IN_FLOW_MAX_FACTOR = 1.3;
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const SPACE_IN_FLOW_MIN_FACTOR = 0.1;
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const SPACE_IN_FLOW_MAX_FACTOR = 0.6;
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const self = this;
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const xref = this.xref;
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@ -2294,18 +2299,15 @@ class PartialEvaluator {
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);
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const scaleCtmX = Math.hypot(textState.ctm[0], textState.ctm[1]);
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textContentItem.textAdvanceScale = scaleCtmX * scaleLineX;
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textContentItem.lastCharSize = textContentItem.lastCharSize || 0;
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const spaceWidth = (font.spaceWidth / 1000) * textState.fontSize;
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if (spaceWidth) {
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textContentItem.spaceWidth = spaceWidth;
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textContentItem.trackingSpaceMin = spaceWidth * TRACKING_SPACE_FACTOR;
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textContentItem.spaceInFlowMin = spaceWidth * SPACE_IN_FLOW_MIN_FACTOR;
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textContentItem.spaceInFlowMax = spaceWidth * SPACE_IN_FLOW_MAX_FACTOR;
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} else {
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textContentItem.spaceWidth = 0;
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textContentItem.trackingSpaceMin = Infinity;
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}
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textContentItem.trackingSpaceMin =
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textState.fontSize * TRACKING_SPACE_FACTOR;
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textContentItem.negativeSpaceMax =
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textState.fontSize * NEGATIVE_SPACE_FACTOR;
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textContentItem.spaceInFlowMin =
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textState.fontSize * SPACE_IN_FLOW_MIN_FACTOR;
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textContentItem.spaceInFlowMax =
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textState.fontSize * SPACE_IN_FLOW_MAX_FACTOR;
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textContentItem.hasEOL = false;
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@ -2395,7 +2397,7 @@ class PartialEvaluator {
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});
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}
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function compareWithLastPosition(fontSize) {
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function compareWithLastPosition() {
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if (
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!combineTextItems ||
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!textState.font ||
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@ -2405,36 +2407,76 @@ class PartialEvaluator {
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}
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const currentTransform = getCurrentTextTransform();
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const posX = currentTransform[4];
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const posY = currentTransform[5];
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const lastPosX = textContentItem.prevTransform[4];
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const lastPosY = textContentItem.prevTransform[5];
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let posX = currentTransform[4];
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let posY = currentTransform[5];
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let lastPosX = textContentItem.prevTransform[4];
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let lastPosY = textContentItem.prevTransform[5];
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if (lastPosX === posX && lastPosY === posY) {
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return;
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}
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const advanceX = (posX - lastPosX) / textContentItem.textAdvanceScale;
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const advanceY = (posY - lastPosY) / textContentItem.textAdvanceScale;
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const HALF_LAST_CHAR = -0.5 * textContentItem.lastCharSize;
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let rotate = 0;
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// Take into account the rotation is the current transform.
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// Only rotations with an angle of 0, 90, 180 or 270 are considered.
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if (
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currentTransform[0] &&
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currentTransform[1] === 0 &&
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currentTransform[2] === 0
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) {
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rotate = currentTransform[0] > 0 ? 0 : 180;
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} else if (
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currentTransform[1] &&
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currentTransform[0] === 0 &&
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currentTransform[3] === 0
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) {
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rotate += currentTransform[1] > 0 ? 90 : 270;
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}
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if (rotate !== 0) {
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switch (rotate) {
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case 90:
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[posX, posY] = [posY, posX];
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[lastPosX, lastPosY] = [lastPosY, lastPosX];
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break;
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case 180:
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[posX, posY, lastPosX, lastPosY] = [
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-posX,
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-posY,
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-lastPosX,
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-lastPosY,
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];
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break;
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case 270:
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[posX, posY] = [-posY, -posX];
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[lastPosX, lastPosY] = [-lastPosY, -lastPosX];
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break;
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}
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}
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if (textState.font.vertical) {
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if (
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Math.abs(advanceX) >
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textContentItem.width /
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textContentItem.textAdvanceScale /* not the same column */
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) {
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const advanceY = (lastPosY - posY) / textContentItem.textAdvanceScale;
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const advanceX = posX - lastPosX;
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if (advanceY < textContentItem.negativeSpaceMax) {
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if (
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Math.abs(advanceX) >
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0.5 * textContentItem.width /* not the same column */
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) {
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appendEOL();
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return;
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}
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flushTextContentItem();
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return;
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}
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if (Math.abs(advanceX) > textContentItem.height) {
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appendEOL();
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return;
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}
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if (HALF_LAST_CHAR > advanceY) {
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return;
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}
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if (advanceY > textContentItem.trackingSpaceMin) {
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if (advanceY <= textContentItem.trackingSpaceMin) {
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textContentItem.height += advanceY;
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} else if (!addFakeSpaces(advanceY, 0, textContentItem.prevTransform)) {
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} else if (!addFakeSpaces(advanceY, textContentItem.prevTransform)) {
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if (textContentItem.str.length === 0) {
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textContent.items.push({
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str: " ",
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@ -2445,7 +2487,6 @@ class PartialEvaluator {
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fontName: textContentItem.fontName,
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hasEOL: false,
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});
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textContentItem.isLastCharWhiteSpace = true;
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} else {
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textContentItem.height += advanceY;
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}
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@ -2454,22 +2495,28 @@ class PartialEvaluator {
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return;
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}
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if (
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Math.abs(advanceY) >
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textContentItem.height /
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textContentItem.textAdvanceScale /* not the same line */
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) {
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appendEOL();
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const advanceX = (posX - lastPosX) / textContentItem.textAdvanceScale;
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const advanceY = posY - lastPosY;
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if (advanceX < textContentItem.negativeSpaceMax) {
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if (
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Math.abs(advanceY) >
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0.5 * textContentItem.height /* not the same line */
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) {
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appendEOL();
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return;
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}
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flushTextContentItem();
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return;
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}
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if (HALF_LAST_CHAR > advanceX) {
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if (Math.abs(advanceY) > textContentItem.height) {
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appendEOL();
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return;
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}
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if (advanceX <= textContentItem.trackingSpaceMin) {
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textContentItem.width += advanceX;
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} else if (!addFakeSpaces(advanceX, 0, textContentItem.prevTransform)) {
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} else if (!addFakeSpaces(advanceX, textContentItem.prevTransform)) {
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if (textContentItem.str.length === 0) {
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textContent.items.push({
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str: " ",
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@ -2480,14 +2527,13 @@ class PartialEvaluator {
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fontName: textContentItem.fontName,
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hasEOL: false,
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});
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textContentItem.isLastCharWhiteSpace = true;
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} else {
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textContentItem.width += advanceX;
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}
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}
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}
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function buildTextContentItem({ chars, extraSpacing, isFirstChunk }) {
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function buildTextContentItem({ chars, extraSpacing }) {
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const font = textState.font;
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if (!chars) {
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// Just move according to the space we have.
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@ -2499,87 +2545,91 @@ class PartialEvaluator {
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0
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);
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} else {
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textState.translateTextMatrix(0, charSpacing);
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textState.translateTextMatrix(0, -charSpacing);
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}
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}
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return;
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}
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const NormalizedUnicodes = getNormalizedUnicodes();
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const glyphs = font.charsToGlyphs(chars);
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const scale = textState.fontMatrix[0] * textState.fontSize;
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if (isFirstChunk) {
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compareWithLastPosition(scale);
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}
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let textChunk = ensureTextContentItem();
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let size = 0;
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let lastCharSize = 0;
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for (let i = 0, ii = glyphs.length; i < ii; i++) {
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const glyph = glyphs[i];
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let charSpacing =
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textState.charSpacing + (i === ii - 1 ? extraSpacing : 0);
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textState.charSpacing + (i + 1 === ii ? extraSpacing : 0);
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let glyphWidth = glyph.width;
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if (font.vertical) {
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glyphWidth = glyph.vmetric ? glyph.vmetric[0] : -glyphWidth;
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}
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let scaledDim = glyphWidth * scale;
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let glyphUnicode = glyph.unicode;
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if (glyph.isSpace) {
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charSpacing += textState.wordSpacing;
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textChunk.isLastCharWhiteSpace = true;
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} else {
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glyphUnicode = NormalizedUnicodes[glyphUnicode] || glyphUnicode;
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glyphUnicode = reverseIfRtl(glyphUnicode);
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textChunk.isLastCharWhiteSpace = false;
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if (
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glyphUnicode === " " &&
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(i === 0 ||
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i + 1 === ii ||
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glyphs[i - 1].unicode === " " ||
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glyphs[i + 1].unicode === " ")
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) {
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// Don't push a " " in the textContentItem
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// (except when it's between two non-spaces chars),
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// it will be done (if required) in next call to
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// compareWithLastPosition.
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// This way we can merge real spaces and spaces due to cursor moves.
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if (!font.vertical) {
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charSpacing += scaledDim + textState.wordSpacing;
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textState.translateTextMatrix(
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charSpacing * textState.textHScale,
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0
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);
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} else {
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charSpacing += -scaledDim + textState.wordSpacing;
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textState.translateTextMatrix(0, -charSpacing);
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}
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continue;
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}
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textChunk.str.push(glyphUnicode);
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const glyphWidth =
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font.vertical && glyph.vmetric ? glyph.vmetric[0] : glyph.width;
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compareWithLastPosition();
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// Must be called after compareWithLastPosition because
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// the textContentItem could have been flushed.
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const textChunk = ensureTextContentItem();
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if (DiacriticRegExp.test(glyph.unicode)) {
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scaledDim = 0;
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}
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let scaledDim = glyphWidth * scale;
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if (!font.vertical) {
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scaledDim *= textState.textHScale;
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textState.translateTextMatrix(scaledDim, 0);
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textChunk.width += scaledDim;
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} else {
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textState.translateTextMatrix(0, scaledDim);
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scaledDim = Math.abs(scaledDim);
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textChunk.height += scaledDim;
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}
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size += scaledDim;
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if (scaledDim) {
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// Save the position of the last visible character.
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textChunk.prevTransform = getCurrentTextTransform();
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}
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glyphUnicode = NormalizedUnicodes[glyphUnicode] || glyphUnicode;
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glyphUnicode = reverseIfRtl(glyphUnicode);
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textChunk.str.push(glyphUnicode);
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if (charSpacing) {
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if (!font.vertical) {
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charSpacing *= textState.textHScale;
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}
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scaledDim += charSpacing;
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const wasSplit =
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charSpacing > textContentItem.trackingSpaceMin &&
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addFakeSpaces(charSpacing, size);
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if (!font.vertical) {
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textState.translateTextMatrix(charSpacing, 0);
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textState.translateTextMatrix(
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charSpacing * textState.textHScale,
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0
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);
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} else {
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textState.translateTextMatrix(0, charSpacing);
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}
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if (wasSplit) {
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textChunk = ensureTextContentItem();
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size = 0;
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} else {
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size += charSpacing;
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textState.translateTextMatrix(0, -charSpacing);
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}
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}
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lastCharSize = scaledDim;
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}
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textChunk.lastCharSize = lastCharSize;
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if (!font.vertical) {
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textChunk.width += size;
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} else {
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textChunk.height += size;
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}
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textChunk.prevTransform = getCurrentTextTransform();
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}
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function appendEOL() {
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@ -2597,19 +2647,15 @@ class PartialEvaluator {
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hasEOL: true,
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});
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}
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textContentItem.isLastCharWhiteSpace = false;
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textContentItem.lastCharSize = 0;
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}
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function addFakeSpaces(width, size, transf = null) {
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function addFakeSpaces(width, transf) {
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if (
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textContentItem.spaceInFlowMin <= width &&
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width <= textContentItem.spaceInFlowMax
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) {
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if (textContentItem.initialized) {
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textContentItem.str.push(" ");
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textContentItem.isLastCharWhiteSpace = true;
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}
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return false;
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}
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@ -2617,22 +2663,12 @@ class PartialEvaluator {
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const fontName = textContentItem.fontName;
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let height = 0;
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width *= textContentItem.textAdvanceScale;
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if (!textContentItem.vertical) {
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textContentItem.width += size;
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} else {
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textContentItem.height += size;
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if (textContentItem.vertical) {
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height = width;
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width = 0;
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}
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flushTextContentItem();
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if (textContentItem.isLastCharWhiteSpace) {
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return true;
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}
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textContentItem.isLastCharWhiteSpace = true;
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textContent.items.push({
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str: " ",
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// TODO: check if using the orientation from last chunk is
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@ -2640,7 +2676,7 @@ class PartialEvaluator {
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dir: "ltr",
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width,
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height,
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transform: transf ? transf : getCurrentTextTransform(),
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transform: transf || getCurrentTextTransform(),
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fontName,
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hasEOL: false,
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});
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@ -2731,15 +2767,12 @@ class PartialEvaluator {
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next(handleSetFont(fontNameArg, null));
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return;
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case OPS.setTextRise:
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flushTextContentItem();
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textState.textRise = args[0];
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break;
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case OPS.setHScale:
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flushTextContentItem();
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textState.textHScale = args[0] / 100;
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break;
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case OPS.setLeading:
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flushTextContentItem();
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textState.leading = args[0];
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break;
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case OPS.moveText:
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@ -2747,13 +2780,11 @@ class PartialEvaluator {
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textState.textMatrix = textState.textLineMatrix.slice();
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break;
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case OPS.setLeadingMoveText:
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flushTextContentItem();
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textState.leading = -args[1];
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textState.translateTextLineMatrix(args[0], args[1]);
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textState.textMatrix = textState.textLineMatrix.slice();
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break;
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case OPS.nextLine:
|
||||
appendEOL();
|
||||
textState.carriageReturn();
|
||||
break;
|
||||
case OPS.setTextMatrix:
|
||||
|
|
@ -2782,7 +2813,6 @@ class PartialEvaluator {
|
|||
textState.wordSpacing = args[0];
|
||||
break;
|
||||
case OPS.beginText:
|
||||
flushTextContentItem();
|
||||
textState.textMatrix = IDENTITY_MATRIX.slice();
|
||||
textState.textLineMatrix = IDENTITY_MATRIX.slice();
|
||||
break;
|
||||
|
|
@ -2795,7 +2825,6 @@ class PartialEvaluator {
|
|||
const spaceFactor =
|
||||
((textState.font.vertical ? 1 : -1) * textState.fontSize) / 1000;
|
||||
const elements = args[0];
|
||||
let isFirstChunk = true;
|
||||
for (let i = 0, ii = elements.length; i < ii - 1; i++) {
|
||||
const item = elements[i];
|
||||
if (typeof item === "string") {
|
||||
|
|
@ -2814,11 +2843,7 @@ class PartialEvaluator {
|
|||
buildTextContentItem({
|
||||
chars: str,
|
||||
extraSpacing: item * spaceFactor,
|
||||
isFirstChunk,
|
||||
});
|
||||
if (str && isFirstChunk) {
|
||||
isFirstChunk = false;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -2833,7 +2858,6 @@ class PartialEvaluator {
|
|||
buildTextContentItem({
|
||||
chars: str,
|
||||
extraSpacing: 0,
|
||||
isFirstChunk,
|
||||
});
|
||||
}
|
||||
break;
|
||||
|
|
@ -2842,11 +2866,9 @@ class PartialEvaluator {
|
|||
self.ensureStateFont(stateManager.state);
|
||||
continue;
|
||||
}
|
||||
|
||||
buildTextContentItem({
|
||||
chars: args[0],
|
||||
extraSpacing: 0,
|
||||
isFirstChunk: true,
|
||||
});
|
||||
break;
|
||||
case OPS.nextLineShowText:
|
||||
|
|
@ -2854,13 +2876,10 @@ class PartialEvaluator {
|
|||
self.ensureStateFont(stateManager.state);
|
||||
continue;
|
||||
}
|
||||
textContentItem.hasEOL = true;
|
||||
flushTextContentItem();
|
||||
textState.carriageReturn();
|
||||
buildTextContentItem({
|
||||
chars: args[0],
|
||||
extraSpacing: 0,
|
||||
isFirstChunk: true,
|
||||
});
|
||||
break;
|
||||
case OPS.nextLineSetSpacingShowText:
|
||||
|
|
@ -2868,15 +2887,12 @@ class PartialEvaluator {
|
|||
self.ensureStateFont(stateManager.state);
|
||||
continue;
|
||||
}
|
||||
textContentItem.hasEOL = true;
|
||||
flushTextContentItem();
|
||||
textState.wordSpacing = args[0];
|
||||
textState.charSpacing = args[1];
|
||||
textState.carriageReturn();
|
||||
buildTextContentItem({
|
||||
chars: args[2],
|
||||
extraSpacing: 0,
|
||||
isFirstChunk: true,
|
||||
});
|
||||
break;
|
||||
case OPS.paintXObject:
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue